Basic ARs, 1911s maybe a few other assorted other items.
1911s would be pretty simple. Take something like a mil-spec springer (not a GI), get the trigger down to a clean 4.25lb break, and offer a few options.
Novak's or Yost Retro sights.
GI or beavertail safety.
Single or ambi safety.
Rail or no rail.
Wood or rubber grips.
Stainless, blued, or parkerized.
ARs would be simple too.
I would offer 20" and 16" barrels, chome lining, 1:7 twist, 1/2x28 threads, government or medium contour profiles. To keep it simple, they'ed all have M4 feedrams (one bbl extension and one upper for all the rifles, makes it easier for me to order from my supplier). Gappers and would also be standard. All would be A3.
For 16" uppers, you'd have a choice between CAR and midlength, and I'll offer both as a dissipator style upper.
20" uppers wouldnt have any options.
A1 or A2 carry handle (both with a same-plane sight), or no carry handle at all. Maybe an A1 verson of RRA Dominator II mount. No point in trying to satify everyone by offering lots of options. Too much inventory for me to keep up with.
A2 or M4 stock. Again, too much inventory.
A2 grip, or an A2 grip minus the finger groove. Again, too much inventory.
If you want me to leave something out/off so you can install something you've got or something I dont offer (like a RRA trigger, LMT bolt assembly, DD forend, etc), that wont be a problem and I'll knock a few bucks off the price.
Being a one-man show, I wouldnt advertise. If I do a good job at building guns, it may keep the business in somewhere between paying bills and me pulling my hair out.
I would call my company KISS Firearms. If you want a tacticool rifle, you can put that crap on there yourself, which is what most of us do anyway...