Seriously, Harbor Freight probably has the best prices on 3/4" socket sets (around $60, IIRC). That will get you several sockets, a ratchet, a breaker bar, and some extensions. They'll work fine for occasional use. Put a long piece of pipe on the end of the breaker bar to the the torque you need to bust the nut loose. Hit it with penetrating oil first if you can and wait an hour before trying.
As far as torquing the bolt to spec, a torque wrench that goes to 600 ft-lb will cost dearly. The biggest from HF only goes to 300 ft-lb. Your best bet for that is to find a friendly mechanic who can loan or rent you one. The other choice is a little blue loctite (removable, especially if you heat it a LITTLE), and a good guess at the proper force needed. Torque specs are mostly to keep the bolt/nut from coming loose due to mechanical vibrations, and as long as you are reasonably close with the torque, the loctite should prevent self-disassembly. Try to remember how much force you used to remove the bolt and use a little less to tighten it. If you use red loctite, you probably won't ever get the bolt free without heating it up to melt the loctite.
Update... If you really want the 600# torque wrench, check EBay... you can probably find one there, new or used, for around $200 including shipping.