Not much anymore. All those items once you have a frame can be purchased over the internet and then shipped without hassle of FFL. your best selection of items are on the net also.
Factory, mass produced semi-custom and handmade custom are all available.
Remember which style you need gen 1 or gen 2. Lots of people make custom stuff anyway you want it, Not as popular as they were in the 1980's but lots available.