Well, first off I have some sad news. My trusty Craftsman compressor has driven its last impact wrench. The motor shorted out and died a few weeks back and the replacement motor costs almost as much as a new one.
I guess now I have an extra 30 gallon tank that I can use for whatever.
Now to your questions...
1st - Do you recommend getting a single stage compressor or one with two stages? I heard that single stages are MUCH louder than dual stages and that could be a factor in my neighborhood.
The answer really depends on your needs. Most compressors you buy these days from Lowes, Sears, or other similar stores are all single stage compressors. In my opinion the most significant difference is in the amount of pressure that can be developed. Most homeowners and shadetree mechanics run power tools that work well with about 100psi of pressure. Therefore, they don't have much need for a compressor that can develop 200psi and it's not worth it to spend the extra money. Granted, the higher pressure allows you to store more air which means the compressor runs less often, but the same thing can be achieved by buying a unit wiht a larger tank.
I'm not aware of any differences with the noise level. My old craftsman compressor was a bit on the loud side - probably comparable to a riding lawn mower with the throttle pulled all the way to down to the idle position. So yes it was a bit noisy but I wouldn't worry about your neighbors calling the cops on you (assuming you've got it in your garage and not in teh back yard).
Here's some more info: http://www.grainger.com/production/info ... ressor.htm
2nd - What are the pros and cons of oil lubricated compressors and the oil-less designs? Can an oil-less one actually handle the needs of restoring a vette?
Well, an oil lubricated compressor will definitely last longer and is much better suited to continuous-use applications (such as sandblasting) since the oil lubrication helps prevent overheating. My old non-lubricated compressor lasted about 5 years before the motor died, but it ran well up until that point. If you plan to do a lot of sangblasting I'd spring for an oil-lubricated unit since it should hold up better for you. I have my eye on a nice looking 240v Ingersol Rand oil lubricated unit that runs about $500 but I'm not sure I can swing the cost (donations are welcome!
3rd - I'm looking at a new 90# capacity pressurized Abrasive Blaster with 8ft hose, 2 nossles, water trap, pressure gauge and hood requiring 6cfm @ 125psi for $100. Seems like a good price, but is it practical for the restoration?
Sounds comparable to what I bought. My sandblaster was bought on E-bay for about $100 and I did my entire chassis, suspension components, etc with it. It worked great for that purpose. By the end some of the components (hoses, valves, etc) were leaking or inoperable due to the wear of the grit going through them, but I think that would be expected with any unit. If I were to do it again, I'd buy the same sandblaster again. Just be sure to buy lots of extra tips - I couldn't find any locally and you really go through them fast (for me 1 tip lasted about 1 hour until it got so worn out and passed so much air that my compressor couldn't develop good pressure).
4th - Do I need to also get an air-powered impact wrench for the restoration? If so, is a 1/2" drive with 250 ft/lbs of torque, 7000rpm, 5/8" bolt capability requiring 5cfm @ 90 psi adaquate? Should I get normal or deep impact sockets or will I need both sets?
Definitely get an impact wrench! 250 ft/lbs should be fine but if you can find one that has higher torque (especially in the reverse setting), that would be a bit better. Definitely go for a 1/2" drive. You shouldn't need to get deep impact sockets, normal sockets should suffice. I actually use my normal Craftsman non-impact sockets in my impact wrench and they hold up well (never had any problems). When you get the impact wrench try to get one that has multiple forward (tighten) settings so you can avoid over-torquing bolts. I have a middle-of-the road Craftsman model and it works great for me.
Well, hope this helps. Good luck and have fun buying your new tools!