I'm kind of a cheese freak myself so I generally don't have a problem with going a bit more out of my way and spending a bit more money than I normally would for good cheese. Although generally overpriced and somewhat trendy in a yuppie sort of way, Whole Foods Market is a chain of stores which specializes in organic and "upscale" food products. One thing they do excel in is wine and cheese. If you're not fortunate enough to live in or near an ethnocentric neighborhood with mom and pop deli's or markets, try to find a Whole Foods (
www.wholefoods.com). Their cheese departments are quite impressive, but be prepared to spend a few dimes.
For my own pizza making, I like to use a mozzerella/provolone blend (about 50/50) and top the pie off with some sort of aged "grating" cheese to get a nice bite. Traditional Sicillian recipies call for parmesan or romano, which are authentic, but I have a fetish for asiago which is a much underappreciated cheese. Generally, you'll find asiago in its "young" form which has roughly the same consistency as provolone. It can actually be used like this as a cheese topping as it melts fairly well and has a bitter, nutty flavor with a bit of nose to it. However, I like to find the aged asiago which is hard like parmesan and romano, but with an even more intense nature. A dusting of this over whatever soft cheeses you've topped your pizza with will give it a good nudge over the edge.
Give it a try...