I would say you've set a pretty realistic budget and machine set for your needs. I would probably pick R-14s for what you discribe (if available). Don't know the pricing on hydralic pivot snow plow, but seems like you left about $12k over tractor price for 3rd function, and impliments, which seems sufficient.
If you can find a used 6-7 ft box blade, it's probably $500 vs $1500 new; but they don't really wear out (heavy use does wear the cutting edges, but most will never see enough use to get to that point).
Make sure you measure the cab height for that garage door, as in the machine set up you actually want to buy, not a BS spec from online, as tire sizes will affect that.
On pricing; check your local rules; but you shouldn't have to pay sales tax for ag equipment.
Discs, turn plows, bale spears, ect are readily available in the used market. Bushhogs are too, but you want to make sure they have the pto shaft, gear box is good, ect; and as a first time operator, maybe better to buy that new with the tractor.
Check out the cab visibility to see the bucket corners too; it's not gonna be on a spec sheet, but will really affect the user experience.
