You are right. As you you stated you won't be ocing so no 'k' model is way to go.
In pc from that link there is 8GB of ram which means that you would need 64bit windows, because 32 bit doesn't "see" more than 4GB.
I have the cd of 64 bit also and I chose a cheaper mobo because the mobo is a p-68 or something which can't recognize IB CPUs and can oc. The mobo I found is a ASRock H77 Pro4/MVP which is $10 or $15 cheaper then the mobo he has and the mobo is meant for IB CPUs and can't oc. And my dad found his old 800w psu in his closet. Idk wat brand it is but it should be ok to bring to the new system. So this is almost $100 under my budget
These are all quality PSUs : Antec, Seasonic, XFX, Corsair , PC Power and Cooling.
Lets hope your old one in one of these. But be careful, if it's faulty it may fry your brand new system. Seeing as were ready to go 1500$ why not buy new PSU, it won't cost more 100$, even less. And if you're prone to saving some money, you can sell that old psu on craigslist or smth. But that's your choice i'm just talking options.