memory ?

[Stregoica]

Hello
I recently put together a pc, this weekend I decided to upgrade it more by buying some ram I bought 2 crucial 512mb sticks the same that I have in there now (different manufacturer though) After doing some more reading online I realize I might have made the wrong desicion . Should I have bought 2 x 1gb sticks of higher speed ram instead of the 4 sticks of 512mb im going to run? In the near future I want to OC my cpu would I be limited using the pc3200/400mhz? If you think I will be better off with 2x 1gb of something please let me know what type. I'd like to spoend less than $225
+ I'd like to get them from new egg . I can allways send the ram thats on its way back or givem to my brother.
Thanks
P4 3.0 800mhz (prescot)
asus P5LD2
200gb sata
evge7900gt co
2x 512 mb ddr2 PC3200/400mhz(240pin)(siemens)