Building your own firearm isn’t that hard to do and if the kit is in stock, you would have it in a few days and a few hours later it would be finished. You need a little patience and some basic skills and tools to complete the tasks, but they are pretty easy.
This is where I bought my Kits and have No Complaints!!
https://www.80percentarms.com/
https://www.80-lower.com/ Better kits at a better price can be had here, in my humble opinion. Nitrided barrels, free-float lightweight guards with torque plates and centering bars for the top rail to line up w/ the receiver, good parts kit and triggers, very affordable. There’s also a pretty good selection of pistol kits (1911, glock, sig, etc)