As far as tubes go I'd recommend trying some out yourself. There are loads of them available. One tip though. The Sovtek EL84M sounds amazing! BUT, I have read reports of Class 5s not coping well with that particular tube. Myself included, sounded awesome and then...smoke. So I'd stay away from that one. VVRs are available from many suppliers. Don't know about the specific one posted in this thread though.