When I dug my 3/4 acre pond, I used my New Holland 2wd 555E to do all the work. I found that if I dug low areas and left a higher area in the pond for driving on, those higher areas dried out for me. I would back in along my roads, dig out into the low areas and pile the dirt on the road. Then when I had about ten yards, give or take, I would drive out and come back in front ways to get a load with the bucket and back out with it.
This worked fairly quickly at digging and removing the dirt, but with winter coming, I became panicked about the rains coming and started just dumping the dirt around the outside of hte pond. This really helped speed things up, and allowed me to keep digging until the rains shut me down. Fortunately I was done and just getting out as much extra as I could.
I spent a full year hauling off that dirt a little at a time. Not having it in there meant that I was in no rush to get it done.
I now have a 5 yard F600 dump truck. It's so much faster at moving dirt. I dig with the backhoe and load right into the bed. The real trick is to park the truck on dry ground.
I think the track loader or skid steer will be a waste of time and money. Tracks are better at getting aroudn in the mud, but not great. Nothing is great at dealing with mud and sometimes you just trade one problem for another that is a lot worse.
How big is this pond right now? How big will it be? How deep? What type of soil and who are you going to get water into it?
Eddie