Clint,
Looks like these came with two different types of
processors, and they aren't changeable, so your stuck with the processor that's in it, but both are good processors with good speed. The memory is going to be either PC2100 or PC4200 depending on the processor type. It has either 256mb 0r 512mb built in with one expansion slot that you can add up to a 512mb chip. Currently, I would recommend running XP versus Vista. Vista still has alot of bugs that they're trying to work out. So, with a general clean up, maintenance, tune up, adding a 512mb chip, and installing XP with all the necessary software and drivers you're looking at around approx $250 plus tax.
I would love to have your business, but my shop is in Missouri, so I'm going to give you a link that has local computer shops in the Houston area. Try contacting one or more of them for a complete estimate, and I'm sure that they'll allow you to ship now and pick up when you get there. I hope this helps you out, and if you need anything else, just ask.
http://local.yahoo.com/TX/Houston/Computers+Electronics/Computer+Stores
Pyrhyc