Don't think you've bought yet, so I'll throw in my two cents.
IB and SB-E are warm in that they are a hotter chip than Sandy, so they require meatier coolers.
To be honest, for simply ripping your dvds and converting into mkv, I doubt you'll need anything particularly powerful. You don't really need to fork out the extra for an i7. I find a 2500k to be more than capable to be honest.
Ripping takes almost no time at all, maybe 10 minutes per disc - but that's more down to my DVD burner, and then it probably takes about half an hour - hour per film to compress. To be honest, I'm not too sure, normally every 10-15 films that I rip, I just leave Handbrake running in the background and the PC doesn't even blink. By the end of the day it's all sorted... If you've got plenty of money though, you might as well get the i7. It's a nice little bonus I guess, and will be slightly better long term.
kd