Planning on getting a RRA Elite CAR A4 upper, and was wondering whether I should go with a carry handle (TAC or A2) for the sights, or get a flip-up BUIS?  I will probably put a scope on it at some point (traditional Bushnell style), if I mount the scope to a TAC handle, will it be too high?

As far as the bipod goes, do I need to get a rail for a handguard to mount it, or can they also mount to the front swivel?

Thanks for the help.

One other question - I'm peicing this together.  If for some reason I go with a 20" A4 upper, anyone have any pics of one with a collapsible stock? I'm wanting to stick with the adjustable so my kids can shoot it comfortably.  Thanks!