Those two changes shouldn't have too much of a downfall right now, though if you plan on this PC lasting, you'll more than likely end up upgrading into them. It's more of a choice for the future of your system than right now, as with either of those setups you should be fine for right now. Granted the i7 and GTX660 would obviously be slightly ahead.
myself right now i would sit on building a pc. you have haswel and the newer gpu going to drop soon. myself i would build a system around a haswell i5 and a amd or nvidia 700 line of cards.for the ssd swap it out for the 520 or the 830/840. the intel 330 at one time had a firmware brick bug and bsod. http://communities.intel.com/thread/33295
they had a lot issues with bsod and firmware on the 330.
If you are looking for a budget build an i5 performance vs the i7 can not be noticed. There is no reason to go with that i7. Drop down to an i5 and grab whatever card you want. The only reason for going i7 would be future proofing on the 2011 socket, but you picked a 1155 build so thats no good. Downscale the i5, and crossfire 7850s is what I would do.
Thanks for the reply. I heard that the i7 is a big boost at the programs i use (flow simulations, i use ansys too for structural studies). Also the card (gtx 660) has cuda cores that help to rendering 3D videos from studio max 3D. I don't know if my informations are accurate!
Seems like a 2011 build would be best for you. Motherboard will be a little more, 230 bucks on newegg, with a 3820, and the rest is the same. That would be ideal for your setup. Definately go with the 660 if you are rendering with studio max. I would look into a z79 2011 build though and see if you can afford that with an i7 3820. I thought this was for gaming. Go 2011, future proof yourself for ivy-e would be my recommendation, have a good night as I am off for bed.