Stifflers is a bit excessive in my opinion. All it does is add weight with no real benefit other than lateral rigidity in the event of a major colision.
Slow my only guess for the difference between the two would be fitment. I personally have the MM set on mine and they fit just fine. That being said, I have never seen the SVE on a car before so I can't vouch for their build quality and fitment. $200 sounds about right. Just make sure the shop has a drive on lift to use to weld them in.
Sold - Black 2000 Mustang GT, gone but definitely not forgotten
- Silver 2007 Corvette
Current - DHG 2001 Bullitt