You cannot have more than 10 imported parts, so you have to plan accordingly. To more directly answer your question, you can use the any stamped AK pattern receiver with the Romie kit. The only time you run into problems is if you try to use an RPK patterned receiver, one of the US made 1.5 mm AK receivers out there or receiver for a folding stock(then you will just have holes you don't want).
If you don't have a muzzle device, you will need 5 US made parts to make the count. 6 if you go with a muzzle device. The highlighted items are the ones that most available as US made. The easiest way to go seems to be US made receiver, hammer/trigger/sear, buttstock and pistol grip. This way you can use any mag you want.
(1) Frames, receivers, receiver castings, forgings or
stampings
(2) Barrels
(3) Mounting blocks (trunions)
(4)*Muzzle attachments
(5) Bolts
(6) Bolt carriers
(7) Gas pistons
(8) Triggers
(9) Hammers
(10) Disconnectors
(11) Buttstocks
(12) Pistol grips
(13) Forearm handguards
(14) Magazine body
(15) Followers to a lesser degree
(16) Floorplates to a lesser degree
