Looking for a Z, and have questions.

I'm looking for a 300zx non-turbo, with a 5sp, low miles, and I would pefer it in silver, without leather, and T-tops. I don't want to spend much more that 12-13k, and need the car to be in the upstate NY and tri-state area. I seem to find a mostly 90's, and I've heard there is a problem with the timing belt and water pump, that requires replacement. Which I don't find to be too much of a concern. I've also heard that there was a design problem in the 90's with the cylinder head, that could cause a large powerloss and also require replacement, this sounds like a big money item to me. Is there anything else that I should be aware of in looking for a car? Any information on any of this, or a good place to find a Z, would be a big help. Thanks