Before anyone says anything, I did check the search and didn't find too much.

I took my car for a quick oil change today (I had a free coupon, so I figured why not) and to check about some coolant leaking. Apparently (according to the mechanic), the cause of this is a blown head gasket. How much do these typically cost to have replaced professionally on a stock 94 Integra LS, what kind should I replace it with, and would it be simpler to replace myself (I don't have a ton of mechanic experience)?