For 2 acres, you probably don't need a 40hp tractor for most jobs, but the side jobs cold change that. It doesn't take much engine power to run hydraulics, so FEL lift capacity is more tied to the tractor size than engine size. Depending on the brand, it's often at the 40hp point where you see a significant increase in size and weight....which normally leads to a jump in price. Will you have a way to load/tow it for the side $ jobs? That can play into how big you want as well....adding a new truck and trailer can get expensive!
I'd also think hard about trying to do side work....will you get a business license, and carry insurance? It's very, very easy to do major damage to things like houses, and cars with a tractor. I've read a bit about side work, like mowing, and brush hogging, and it seems most folks doing it are barely breaking even after everything is added in....fuel, wear and repairs, etc. It can be done, but it does take some thought and careful planning. Just one mistake can tear the gearbox out of a mower, or brush cutter, and that needs to be factored in. My very experienced neighbor (has five tractors) borrowed my 5' cutter yesterday because his needed some welding, and he didnt want to use his 6' cutter on his bigger tractor. Within half an hour, he killed the gearbox (he's going to replace it)....stuff happens, so it's worth considering.
After all of that, I'd say try to drive as many brands, and models as possible....you'll be surprised what you do/don't like, and how much prices can vary for similar capability units from different manufacturers.
