You can't go wrong with a VHT, but it's not totally necessary. I'm not familiar with Carvin power amps. I am familiar with ADA, Rocktron, VHT, and Mesa power amps, and whether they're SS or tube, the results are comparable with a slight difference in tone.
If you have a lead on a Carvin, then you should try it out first, if possible. If it is a SS amp meant for their PA gear, then you may not get a sound you're happy with.
On another note, I've read hear on the forum that some prefer the RM50 tone over the RM100.
BTW, I was trying really hard to not be biased... :wink: