Just picked up two DPMS lowers.

I know that collapsible stocks were banned last time, but what else do I need to go ahead and pick up now?  Im not looking to finish these guys, just want to get the parts that I may not be able to pick up later.

Thanks.

Nobody knows what will be banned.  If there is a ban, you might be OK if you just have the lowers.   There might be a ban which affects other parts.  Barrels or upper receivers could be affected.  If there's a ban it could ban them if they aren't completely assembled on the day it takes affect.  I would recommend you get enough parts to assemble at least one complete AR, and try to at least have the 2nd one built into a complete lower to cover as many bases as possible.

one will be a Noveske 10.5" CQB 5.56mm Upper with VIS if they have one in stock.

The other will be a bench gun.

Four more lowers. If/when the next ban comes they'll have no way of knowing what you built when. As long as the stripped lowers have a preban build date you'll be able to configure them as you like. After a few lowers I'd concentrate on ammo, primers, and brass.

Ive already got 2 AR15s.  Don't need 4 more.

RRA Entry tactical
Sig 556

These two are going to be made into a SBR (starting paperwork now) and a bench gun.