porting cost?

It all depends. Parts costs are only about 50% of a build like you mention you need. So having gaskets, a timing chain, and an intake and carb, mean very little. You dont have (I'm guessing, tell me if I'm wrong...) you dont have pistons, rings, bearings, core plugs and pipe plugs, the dist bushing, the dist drive, valve springs, water pump, oil pump, pickup screen, the cam, or lifters. Those are what the machinist will need to rebuild it. That's where the costs are. I'd prefer to have a well machined stock short, and stock intake and carb, than a POS shortblock, and a nice carb and intake I'll go faster on "good stock".