The pump is hard to find? It's a 2 section pump with an SAE A pattern and a 9 spline 5/8" shaft. When it comes time to replace mine I'll be going with a single section pump. As is, one section is half the size of the other, and nearly ALL the time I have it set so the large section feeds the drive/loader/aux on the boom while the small section does nothing as I hardly ever use the other aux hydros.
http://www.surpluscenter.com/item.asp?UID=2008112115402417&item=9-4848-A&catname=hydraulic
That did take all of 3 minutes to find for $105.99. Sure I'll lose my second circuit of aux hydros, but I'll increase everything else's speed by 50%, which is just NICE
The wheel motors are Parkers. fwiw.
If you can walk on the ground without needing rubber boots, you shouldn't have much trouble. I've never had mine stuck to the point I had to use something else to pull me out, only a sheet of plywood. I have needed something else to roll the machine back over on it's tires a few times.
The only really wet job I've done, the mini got in and out where the full size skid steer (1500lb cap bobcat on tires) got stuck twice and had to be pulled out with a truck.