serial ata problems help!!!!

hmm yea i just ordered a computer off the internet and i ordered a serial ata hard drive by mistake so since i heard that u could still use the sata hard drive i figured ill ask here can u guys tell me whats a good pci adapter for it and can you guys explain me witch raid thing should i use like whats the best one plz help me



components

xfx mach 4 nvidia nf2s-alh
xfx geforcefx 256mb
amd xp 2500
maxtor diamondplus 9 SERIAL ATA (PROBLEM)
2gb 3200 ram 400
dual dvd+rw