In fact, in my previous post I was lost in memories. I had a Celeron CPU with a S3-like video card a long time ago...
Anyway, I would not recommend to spend any money in a partial upgrade of this computer. It's too old. Derrek should save his money until he can buy a real recent computer, that will save him a lot of troubles, in my opinion. Don't you think ?
All depends on what he'll be able to afford. Fact is, I started out my FS9 days on pretty similar hardware too, but I did it the other way. One small upgrade at a time. Personally, if I had had to wait for a major upgrade, I would likely have lost interest in the sim altogether. With small, individual upgrades, at least he'd be simming while saving for that big overhaul. Do what you can, where you are, with what you have, I always say. Just my two cents.
Anyway, which every way you decide to go Derrek, be it several small upgrades, or one big one, an upgrade of some kind is warranted for the performance and eyecandy you're looking for.