You dont theoretically need an aftermarket heatsink but your processor will overclock itself to handle specific applications. So in conclusion you will get higher temps even without overclocking for certain applications. If you do choose an aftermarket heatsink i would suggest the corsair a70 which comes out to $33 after rebate and makes the hyper 212+ look like an oem heatsink in the same price range.
Your right syxxnyne69. The H70 is better especially if it has a that rebate. And you can stay with the ram you selected if you go with the i5 and MSI mobo. If you go with the i7 then you will have to change to a set of triple channel memory.
i5: What you have is good or go with g skill to save a little money.
i7:Mushkin Enhanced Blackline 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model 998778
G.SKILL 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Triple Channel Kit Desktop Memory Model F3-12800CL9T-6GBNQ