I'm also building up a 2.5L TIII. Mine uses a TIII block, cast 2.5L TI crank, TIII rods, Venolia custom pistons from fwdperformance.com, and no balance shafts. Also used ARP rod bolts and main studs for it. Probably going to use one of my stock TIII heads w/Ti retainers, a Garrett 60-trim T3 turbocharger from a Mustang SVO. Only looking for ~280 WHP with plenty of torque for a super fun daily driver in my SL. Also got a nice A568/A523 hybrid with 3.77 gears and an OBX from Cliff Ramsdell and a blue plate/6-puck clutch and lightweight steel flywheel from Turbos Unleashed.
What are you using for a calibration? I'm going to start off with the stock TIII SBEC, but hopefully will find something a little better later on.