If you decide to go with the D16z6 I have one that was being built for ITA.  I have lots of good parts for it.  Canton oil pan, Hytech header, ARP rod bolts.  All the machine work is almost done.  PM me if you are interested.  With just a few changes it could be a good start to an FP engine.  Just add 12 to 1 pistons, better valve springs, which I have and a legal cam.
Blake Meredith