a/ I made one just by bolting a 4age head straight onto a 7afe complete bottom end. Standard everything. Ran fine, drove like a 4age with a bit more bottom end pull. Exhaust has to be modified to clear sump for fwd applications, cambelt is Porsche 944 item for 4age 16V heads.
b/ Apparently the weakest part of the 7afe rods is the big end bolt attachment and this can be modified to accept stronger attachment (ARP stud and nuts?) Also standard Bigport 4ages start running out of puff before 7000 rpm, so unless you are planning to really flog it a lot, it MIGHT NOT be worth the expense of custom rods. (Just don't blame me if you build one and it craps itself, lol)