I can relate, just finished grouting the kitchen last night. The room
never seemed so big.
I have a 30 gallon Craftsman that has been great. Just bought two PC
nailers for the reasons you mentioned. Before you buy a compressor
think about this:
Does it need to be portable?
Will I ever have the need for an HVLP sprayer? (don't know much about
this, but I gather it requires a special or high-volume compressor)
Space available (next time I will get one with a vertical tank for a
Noise level of the compressor, wife, kids, neighbors, etc.
What kind of tools will you need to run? As already mentioned, nailers
don't need a big tank, except maybe a roofing gun. Air tools like
grinders, drills, ratchets, impact guns and the like use a lot of air.
My 30 gallon at times can't keep up when using these tools.
As usual the answer is: It depends...
What about brazing the hole in the tank or having it welded?