<p>I use a Matrix power amp into Mission cabs. I ran my Matrix into marshall cabs twice at different shows and loved it both times. It sounded alot like the marshall cab I use with my frfr setup. Long story short, find a cab that sounds like your marshall (they are out there) or profile that cab yourself and run it through your frfr.</p>
What would be the recommended power amps for this?
If you have a toaster. you can get one that fits into the space at the back for ultimate portability. Otherwise, you'll have to get something external.
What kind of power are you looking at?
Jesone, I am not sure what you're missing: just a way to control your amp's volume? A volume pedal set to "post stack" will work as you Marshall's pre would.
HTH 
