I got my rotating assembly from a vender on here , he's from Ky but I cant remember his name, I got eagle 4340 crank, forged h beam rods and forged srp 13 to 1 pistons all necessary rings and bearings all for about $ 1700 delivered.
I would definetly get the rotating assembly balanced regardless if your going internal or external and even if you buy one of those so called "BALANCED ASSEMBLIES", it's the right thing to do and is well worth the extra bucks as far as longivety is concerned. Do you plan on running pump gas? or plan on adding any power boosters later?