Oh, to answer your questions:
The six to me, is the way to go. But it can end up costing you quite a few dollars. By the time you get the motor, you may or may not need a front mount oil cooler, the six mounting bar, brake/suspension upgrades, it can run you a lot.
But, you can probably pick up a half way decent motor, the quick six bar, and put it all in for not that bad.
Check out 914club.com.
- Brett