I might go with 850cc primaries instead of the 550s. If you don't have one already you should look into getting a boost gauge as well. I would also suggest an ignition upgrade, the HKS twinpower would probably the easiest plug and play option. While your engine is out check your motor mounts and wiring harness. If your motor mounts are worn I would recommend replacing them with noltec motor mounts while the engine is out. Do you have the stock radiator still? That could be a weak point in your system and wouldn't be a bad idea to change out to an all aluminum one as well. As far as the block off kit goes Banzai racing has the cheapest one I have found so far.
http://www.banzai-racing.com/