Unless I'm mistaken, SWG needs at least a DX7-class card...now, much as I love the concept of the Kyro/KII, DX7 it ain't...so it's upgrade time for you!
Now, depending on your budget, there's three real options...
At $76 - A Radeon 9100. Don't be fooled by the name...it's a fair bit faster than a 9200. Do not touch the GeForce FX5200 with a bargepole...sure, it has all the nifty features, but it ain't fast enough to run them.
(N82E16814102264 - Insert this into Newegg.com's search bar to go straight to the item.)
At $125 - EITHER a Radeon 9600 OR a GeForce4 Ti4200. The R9600 will perform quite a bit better, and has all the spiffy DX9 features, but some people have these irrational clingings to nVidia...and the GF4 isn't a bad card, especially if you overclock it. The GeForce FX5600 isn't mentioned here (Heh...) because the only ones with even acceptable performance (i.e Faster than a Ti4200) are nearly $200.
(N82E16814142012 for 9600, N82E16814260016 for the GF4)
At $280 - A Radeon 9800 non-Pro. Now, this'll be slightly slower than a 9700 Pro ($292), and faster than a 9700 non-Pro, and it's priced just between those two; while all 3 are viable options, it's worth noting that the only 9700 NP I could find on Newegg is from a manufacturer I've never heard of, and that the 9800 NP can be overclocked quite a bit...usually above 9700 Pro speeds.
On the nVidia side, we have...well. FX5900 and FX5900 Ultra. The FX5900 is priced at $360, and performs about as well as a 9700 NP ($240), while the Ultra (On Newegg; you could probably buy it for less in a shop) costs about $400 upwards, and, depending on what drivers you use (Long story...basically, nVidia altered their drivers to diminish image quality without the user's knowledge, artificially inflating speeds) is either as fast as a 9800 Pro or as 'slow' as a 9700 Pro.
(N82E16814102292 for 9800 NP, N82E16814102254 for 9700 Pro - If you want to buy a GFFX, dig your own grave.