Just to clarify something ... NO beadlock wheel is DOT "approved"
. There are some that are DOT "compliant" meaning they meet DOT's wheel construction standards. Problem is, there are no specific DOT regs/specs regarding beadlock wheels. Also, the NHTSA, last time I looked, has no regs on the books specific to beadlocks - but, they could regulate them if someone there decided they were a safety risk.
Here's where the grey area comes in
... just because a wheel is DOT compliant doesn't mean it's legal for use on the road (doesn't necessarily mean it's illegal, either). The Society of Automotive Engineers (SAE) created standards for aftermarket wheels (SAE J2530) that the industry adheres to for wheels intended to be used on public roads. The problem with typical beadlocks is that using rings to clamp the bead of a tire to a rim doesn't meet SAE J2530 ... so they are not SAE compliant.
AEV does say that their wheels have passed SAE's tests for "Radial Fatigue, Impact, and Cornering Fatigue". But, as I understand it, their beadlock wheels are still not SAE-compliant by virtue of using a bolt-on ring to clamp the tire bead to the rim.
The only beadlock rims that I know of that are DOT and SAE compliant are the Hutchisons. As it turns out, they are also the most expensive at $400 per wheel.
I've been eyeing a set for a while ... but, damn, that's expensive.
Despite 'compliance', they are arguably better than a traditional beadlock because they clamp both beads
of the tire.
Also, you may want to look at Staun internal beadlocks. They use an internal bladder to turn any wheel into a beadlock. They also 'lock' both beads.
Finally, you didn't mention if you had ever had beadlocks before. But, if you haven't run them, be prepared for lots of maintenance. I've had several - great off road, but they can be a pain.