I use the Stampede shafts and I have yet to break one....seem to hold up well. I bought the 6-pack of them so they should last a bit. You could always go with the MIP shafts....top notch stuff there.
You can use maxx shafts, you just have to get some CDW outputs for the ax-10 tranny . Search on rccrawler.com for yotacump, he is the producer of the said outputs for the ax-10 tranny. You can also put a metal pede yoke inside a maxx yoke IF you has accsess to a lathe.
Smaxxin, a lot of people just modify the outdrives on the tranny and run Maxx shafts. There are tons of custom driveshaft options.
If you have to buy something from Traxxas, it's not much more money to get the MIP's if the legnth will work for you.
Also, I have a bunch of Revo driveshafts I think, if you need a couple. They're super big though, I think they're axle shafts but I'm not sure, got em in a trade with some stuff and never took them out of the bag.
Also, the stuff that yotachump makes is top notch. He's one of my favorite vendors for crawler parts, besides myself of course