There are pros and cons to each defensive scheme, but the differences between the schemes call for different types of players at certain key positions. Based on our current personnel, I believe the 4-3 defense is the most appropriate defense for us at this time.
First off, in a 3-4 defense you need a BIG nose guard, as his job is essentially to plug up the middle and eat up blockers. If you look at our roster, we really only have one guy like that, JC transfer Sumter. Based on the fact that he has never played a down of D1 college football, I wouldn't feel very confident trusting him to do the job. Even if he was capable, we really have no other players to give him a break or take over for him in the case that he was injured.
Furthermore, the other two down lineman in a 3-4 defense are very similar to the types of players you would see playing DT in a 4-3 defense (think about how big both Fletcher and Unrein were). Now, this doesn't bode well for us as one of our thinnest and weakest positions on the team is that DT position.
Finally, the outside linebackers in a 3-4 are ideally exeptional athletes. The OLB's in the 3-4 are the primary pass rushers, so they have to be big enough to take on a offensive tackle, but they also must be nimble enough to drop into pass coverage. I don't really feel like we have anybody who fits that mold on the current roster. We do have some athletic LB's, but they don't possess the size necessary to be able to take an O-tackle on and win.