You can OC a 2500k more than a 2500, but both have potential. Your original mobo of choice is not really a good OC platform (compared to others). Given your budget, your options are going to be limited.
That being said, you really don't need to OC the 2500k or 2500 to get very good performance. Nice to have, but not essential.
i know, but a 2500 can oc 400mhz higher with no issues so i mean why not get the 2500? i've never done any ocing above 600mhz, i did a e8400 from 3.0 to 3.6 and thats it, so im thinking a good 80-120$ p67 board, a i5 2500 and some ram would be good?