Laurent, I have an any-size steel reel that I made in a few minutes. I just cut the steel reel in half and reattached the some pieces with hollow aluminum tube, which were then crimped to keep the right size. The thin base means you can bend it very easily. There are probably some 70mm reels coming onto the used market too, I'd just watch ebay. I do know a few labs still process it.
In case it's useful, I'll insert some points from another forum, in which someone pointed out that the effective cost per roll is roughly the same you'd currently pay for 120 acros at freestyle. Obviously, people need to do their own math and decide whether it makes sense for them. It makes sense to me because (1) I never claimed this to be identical to plus-x but as a matter of fact, I like the extended red sensitivity; (2) when you purchase a bulk roll like this your price is "locked in" for a very long time (!);(2b) you also have very consistent material to work with for along time; (3) the thin base doesn't bother me in the least, I have panatomic x on estar and love it - you can fit a lot of exposures in one little canister- the 70mm backs aren't that much bigger than the 120/220 ones; (4) you can cut it down to use it in a number of ways; and (5) if it isn't for you then just don't buy it.. but don't moan a year from now about not having any Kodak either