Anyone ever deal with this company? Good or bad?

Great movie...did you see the gun he carries?  

Oops. Supposed to be Hellbox.

What do you need to buy from Hellbox we may be able to send you to some place that we have done business with.

Looking for a center support bushing. The reason I was looking at their's is that they're the only ones that state they make them long so you can trim them to size.

If you have a drill press with a vice on it you can make one yourself.
All you need to do is get a 5/16 socket head bolt about 3.5" to 4" long cut the head off & the threaded end so all you have is the shaft.
Find a drill bit just larger than the rivet you will be using & mount it in the drill chuck point up. Lower the quill on the drill press & center the drill bit in the vice (mounted on the table)and clamp down on it. Release the drill bit from the chuck & let the quill retract, now chuck up on the piece of 5/16 bolt shaft.
As you slowly advance the quill while running the drill press let the drill center itself on the stock then keep light pressure & let the drill cut, retracting every 1/16" or so to let the chips clear. You can use spray oil or WD-40 to keep the drill bit cool. With the shaft spinning the drill will stay centered all the way through the new center support, cut it to size and you are good to go.