Fox, That huge compressor is always nice it makes a lot of other things possible

Torque wrench-DO NOT scrimp here, get the best you can afford such as a Snap-on, Mac,Proto or S/K, Harbor Freight has genuine S/K for about $89.95 if you need a budget wrench. The cheapies can not be trusted and could cause you major headaches and cost you $$$$$$. Jack and a GOOD set of jack stands? Pullers? Valve and valve spring tools? A GOOD gasket scraper? Swivel sockets(very handy but get the good ones cheapies will break), Impact sockets? Pry bars? This is only a start and it could make a long list but these are very handy and if you don't have them already you might want to add them. This really is a good question and if you will tell us what your project is going to be I am sure others will have good ideas as to what you will need before you start.
Good luck, have fun and work SAFELY