What kind of overclock can I expect with this?

 cpu-2700k

motherboard-asus p8z77-lk

The heat sink and supplies I plan on using to set up a push pull.

http://www.amazon.com/gp/product/B005O65JXI/ref=ox_sc_act_title_2?ie=UTF8&smid=ATVPDKIKX0DER

http://www.amazon.com/gp/product/B0045JCFLY/ref=ox_sc_act_title_1?ie=UTF8&smid=A23NVCSO4PYH3S

http://www.amazon.com/gp/product/B007RESFYK/ref=ox_sc_act_title_1?ie=UTF8&smid=ATVPDKIKX0DER

I'd expect somewhere around 4-4.5GHz, where at that boundary, it's the most stable and where the CPU will run at decent temps.

Thanks for the feedback.

you don't need push pull with two SP120s

there will be too much pressure

Won't that be a good thing. You need pressure when pushing air through a phinned heat sink.