Need help deciding on Yamaha keyboard

Hi, with my budget, I'm looking at the PSR 240 and 270. I looked at the yamaha website, but the specs look so similar, except for GMIDI and more voices on the 270.
I plan to use it for practice and composing on my PC and SB AWE32 sound card. So I'm wondering if the GMIDI and voices are worth the ~$60 difference in stores. Any opinions? Thanks

If you want to use your keyboard with your computer, you need GM MIDI... so the 270 is the one that will work for you. Also, you will outgrow the 270 less quickly, as it has more to work with.