I can't help you out at all with the prices, but I will also recommend 4 wheel drive first and hydro tranny second.
I would also recommend that you budget for a loader right from the start as well. With the competitive finance rates available, you might be able to get all of this and almost stay within your budget.
Assuming you're planning on keeping this tractor for a long time, then the additional cost is well worth it over the life of the tractor. If you're not planning on keeping it that long, it is the opinion of some that a 4WD and hydro tractor will sell easier on the used market. I'm sure a loader will help too.
Of course, most of us here are pretty good at getting others to spend their $.
Good Luck,
~Rick