I'm not sure the terminator priest is worth it. He's only giving you furious charge, since feel no pain is pretty useless on terminators. Give your terminators all hammers and he won't be worth it at all.
But maybe that's just the black templar player with his crap storm shields and 3 point furious charge upgrade talking.
You also have one priest per squad (excepting death company who don't need one) when you can usually keep two squads in the range of one priest.
Its boring, but its probably best to go "all in rhinos and razorbacks" or "all wearing jump packs" rather than a mix. Most armies are a mix of anti tank and anti infantry, so you're basically just giving everything in your enemy's army its perfect target.