With 100 acres to handle, you need a big tractor - 50-60 hp (pto).
What's your 5-year plan? Do you want to start with a smaller tractor (35-40 hp), pay it off and then trade it as part of a deal for a larger tractor?
Food plots: How large are your food plots? Do you want to do conventional tilling/planting or are you planning to do no-till planting?
Field mowing: How many acres? How many acres per hour mowing speed?
Brush mowing in your woods: How many acres? How fast do you want to do this type of mowing?
Landscape work: how many acres? Large tractors can tear up a lawn if you're not careful when you mow.
I started out in 2005 with a new Kubota B7510HST (21 hp engine, 17 hp pto, 4WD, hydrostatic tranny, power steering) with the LA302 FEL (4-ft wide bucket, 800 lb lift to about 7 ft height). It was fine for work around my 10 acre place (flat pasture) while my house was being built (landscaping, mowing the weeds in the hayfield, general toting work with the FEL). I paid it off and, after deciding I wanted to get 6 acres into hay production (as a hobby, not a business), I traded that 7510 as part of a deal for a new 2008 Mahindra 5525 (54 hp engine, 45 hp pto, 2WD, gear tranny 8F/2R, power steering, triple hydraulic rear remotes)with the ML250 FEL (6-ft wide bucket, 2950 lb lift to 10.5 ft high, skid steer quick attach option). Paid $12,600 for the Kubota and about $19K for the 5525. I mow with a 6-ft Hawkline brush hog.
Good luck