and one more thing. should i ditch the gateway and bulid my own pc?
Depends how much the gateway costs.
I recently priced out making a system prom parts ordered on Newegg, you could make a real nice Athlon64 3500+ with 1gb of RAM and a 7600 GT for under $900... and that's with windowsXP and a 17" LCD monitor included.
Without the OS, you could get all that for under $800.