Which mfg for 38 super BE project?

I have a group of 45's all but one have had serious work done on them for BE.
Not having enough to do, I am looking at shooting 38 super, downloaded to BE levels
As another way to enjoy shooting 38 caliber.
I noticed one can buy a basic 45 govt model for less than $1000, which seems like it might
be ok for a project gun. 
The question: Any fatal flaws in this idea?  Colt good enough? (never thought I would ask that)

38 super and 45 have different head diameter so you are better off using a 9mm 1911 as the base for a 38 super.  38 supercomp brass is the same head diameter as 9mm.

I have a Springfield Armory Range Officer that started life as a 9mm.  Jon Eulette put a KKM 38super barrel in it so I could run it as an EIC pistol.  It shoots 115gr HAP jhps into 1.25" at 50yds.  It even feeds and shoots 148gr button-nose wadcutters with 2.8gr of Bullseye nicely in the 10-ring at 25yds.  And recoil?  What's  that?

I have recently gotten several 38 Supers and like them. I have a standard model Colt 1911 that shot surprisingly well but fitted a 10 twist KKM barrel and BoMar type sights. I use Zero 147 bullets and can get sub 3 inch at 50 yards. I have been trying some lead and coated bullets but haven’t been happy with the results so far. 
Rush

9mm Range Officer converted to .38 Super, breech required to be massaged a tad for rim clearance. .38sc would just require mags and barrel fitment, if lucky. I haven't downloaded any rounds for it as 185gr .45 gives me a larger scoring hole and one less gun and mags to carry.

Sc0 wrote:9mm Range Officer converted to .38 Super, breech required to be massaged a tad for rim clearance.  .38sc would just require mags and barrel fitment, if lucky.  I haven't downloaded any rounds for it as 185gr .45 gives me a larger scoring hole and one less gun and mags to carry.

actually, super-comp .38 brass fits perfectly in that 9mm.

james r chapman wrote:actually, super-comp .38 brass fits perfectly in that 9mm.

I can vouch for that!  Ed Brown magazines also function 100% with 115 HAP,  147fmj,125swc, 148bnwc and 150swc.  

I tried Wilson 9mm magazines with 38 super followers and the spacer removed but the feed lips were too long and didn't release the round soon enough.

If anyone else commented, sorry, I missed it.

Most .45s do not have a ramped or fully supported chamber. Most modern manufacture .38 Super and 9mm have a supported or ramped barrel. The original question was about frames to start with. If you start with a standard .45 frame, then you will most likely need to have the frame cut to receive the supported barrel of a .38 Super build. Basically, you have the Wilson/Nowlin cut or the Clark/Para cut. Therefore, make sure the ramped barrel is for the proper cut in the frame. If you start with a used .38 Super or 9mm frame or gun, make certain that the barrel and frame cut are standard W/N or C/P fitments. There are a few who have modified those fitments claiming a better mouse trap. I would start with a known, new frame, with the cut matching the barrel that you intend to use. The ejector will be different too between the .45 and 9mm/.38 Super. I have never had bad luck with Caspian frames.

Of the custom .38 Supers that I own or have owned, all would handle .38 Super or .38 Super Comp brass. I only had to adjust extractor tension to get them to run. Some once setup would run as either brass as long as I stayed with the same brand brass, that they were set up for and how many times the brass may bounced off of concrete, damaging the rims. It is best to use either Super or SC brass and not mix them.

In my experience, it is easier to find several loads or variations of .38 Super or SC which will shoot accurately than it is to find that 9mm load which will shoot as good. Both will shoot equally as good, I just find 9mm more difficult with fewer acceptable options. 

Magazines are another issue. In many cases you can use 1911 .38 Super magazines in a 9mm 1911, but not conversely. I mostly used Wilson .38 Super mags. I don't think they catalog them any longer. There are other magazines 9mm and .38 Super which are available and work fine.

If I had it to do over again, all of my .38 Supers would be 9mm. Component hardship from time to time, and the readily availability of loaded inexpensive 9mm ammo would give 9mm the edge. Things were different over 25 years regarding 9mm and .38 Super when building tack driving reliable custom pistols.

Enjoy the journey...

Why not buy a 1911 that is chambered for 38 super right out of the box, I see that Colt has a blued steel gold cup for 1349 on their website.  Rock Island has 3 1911's and Tisa has one but it has a chrome finish.  Of course if you want a project gun and there is nothing wrong with that then the other posters know much more than I do.  Good luck with your project.

I've been happy with my RIA 38 super. From what I've seen of Tisas quality, I'd seriously consider one of those. The RIA was a GI model and had a fast twist barrel which would likely work fine for heavy slow bullets but I opted to drop in an inexpensive Sig barrel which worked great with minimal fitting. I shoot 125g bullets with new SC brass. If I had to do it again I would try to get the pistol version that has the extra goodies on it (adjustable sights etc.) If available. The pistol is plenty accurate. One issue with the RIAs is they have a proprietary sight dovetail cut. My pistols are functional only so if you are looking for pedigree or to induce shiny gun envy on the line, the RIA maybe isn't the way to go.