I used to get my rootstocks from Deacon's but since I've found that they have supplied me with so many wrong varieties in past years, and won't answer my correspondence on this matter, I feel disinclined to give them any more of my custon. I contacted Frank Matthews, who will supply EMLA stocks in reasonably small quantities, a minimum of 10 per type. I've emailed a couple of other suppliers, but no reply so far.
Most of what I'll need are Quince A. Although I started off with QC originally, I made a conscious decision to change as there isn't a lot of difference in vigour (of my original cordon of 4 pears, I now cannot tell the difference between the 3 on QC and the one on QA in size; the bark splitting on the former is a good indication however). I also now find that some QC stocks weren't virus free in the past.
Apples are more of a problem. I don't like M26 for reasons given earlier (lack of vigour, late onset of fruiting, breaking branches, rampant suckering and susceptibility to woolly aphid). However, it is marginally more damp tolerant than MM106, something I can vouch for having not having lost any trees when had 18" of standing flood water for 2 months in the summer of 2007. I'm impressed with the productivity and growth habit M27, and would certainly use this if planting apple cordons now, but I would like a couple more half-standard apples to include some tip-bearing varieties I haven't had room for before.
The best apple stock for damp conditions appears to be M111 inter-scions. I will have to look into these further as it's a certainty that we are flooded at least once a year.
more on rootstocks/propagation: