Sounds allot like my situation but I have a little more of it, under an acre though, i have the hills, 16 trees, several bushes & flower beds and the play set I have to mow around, I bought a 2011 Cub Cadet GT2100 and it handles it perfectly, tight 18" turning radius also. Cub uses a Kohler OHV V twin with full pressure oil system (a must for operating at angles) connected with a drive shaft (no belts to slip or break) directly to a heavy duty cast iron hydrostatic transmission with large fluid capacity and spin on filter. Cub sells the decks separately so you can buy the one that best fits your needs, I have the 42" stamped deck with the mulch kit, that might be a good option for you also. Just make sure you can mow up and down the hills & make your turns on flat ground, don't side hill it if you can help it, tip hazard. I did liquid fill my rear tires and it added some stability for me and helped with traction also. I would avoid anything from a box store, go to a real equipment dealer, they will have the better quality units, have them set up properly and actually have some product knowledge. My unit with the deck cost me about $4000 and has an up to 5 year 500 hour warranty, the closest comparable green tractor I found costs twice as much. The GT200 series is a well made stable machine, with the deck it weighs about 1/2 ton, check them out, I believe them to be the best deal for a real "garden tractor" out there. I also use mine for towing a dump trailer, aerator and clearing snow with my 46" snow blade. (See photos :~)
