Updating imac hardware

I wouldn't think so. You can upgrade a few parts with the Mac Pro, but I don't think so with the iMac.

I believe you can only update the Ram you might be able to update the GPU but not the processor

Thats the down side to a Mac. They have very closed hardware setups so upgrading is near impossible or just damn expensive.

In short, no. You would not be able to upgrade to a i7 from a i5 if you get a Mac.

If you want the upgradeability option, you are best off going PC.

Or buy a new iMac.