Wut should i replace while my new motors accessible?

Im putting a 7 bolt motor with 30k miles into my 96 GSX. Before I put this motor in, i wanted to ask if I should replace anything on the new motor. (Gaskets, seals, anything). Im putting an ACT 2600, UICP, 1g bov, MBC, Boost gauge, intake filter, plugs and wires, timing belt.

Should I replace anything else while the motors out. Do I need to replace the balance shaft belt, and tensioner? Should I replace the rear AND front main crank seals? Any help would be appreciated.

BTW, im on a very tight budget. I only want necessary and practical replacements.

If you eliminate the balance shaft, the belt and tensioner will come with it. That's all I know. :)