The thing about the frame is you need special tools to get the rails right so the slide and frame fit within the tolerances you want. You risk cracking the frame if you are not careful.
Maybe you should consider buying the frame from a shop that you can send the slide to (no FFL needed) and have them fit the slide on the frame before they ship it to you. This particular excercise (fitting the frame/slide), isn't the "zen" of building a 1911 IMO. It's the fine detail work to fit all the other pieces and making them work well together that make building a 1911 interesting.
Fusion will sell you a frame and fit it to your slide. They have several designs of frames you can choose from. You can also buy a barrel from them and have them fit the barrel and bushing to the slide. It all depends on how much you want them to do. I found their prices for frames and barrels was very competitive.
I would then buy the other smaller parts from Wilson or Ed Brown, etc.
Get the Kuhnhausen manual,
"The Colt .45 Automatic: A Shop Manual Volume 1" Book by Jerry Kuhnhausen - MidwayUSA
Just Vol 1 will do. I'm an engineer and I like to see drawings and numbers, so I got Vol 2. Not really required, but I like it.
Get a good set of small files. Actually I just got a couple of small sets from Harbor freight and they work great. Cheap and useful.
You'll need a few other tools specific to the build (plunger tube tool, gunsmith block 0but 2x4 with holes drilled works well too, dremel + attachments), but they aren't that expensive. You will end up spending more in the end than buying a Springfield GI, but the excercise is good for the soul if you like mechanical things and like to work with your hands.
Get some stones for the sear and hammer.
Search for 'nuttinfancy's" Youtube video from his visit to the gunsmith. Good quick video of what you're in for with the sear and hammer. Not too scary.
Just remember, this is a firearm. If you are not confident of your ability, you must farm it out. This is not like fixing a 1911 where your screw up may just mean a trip to the mechanic....