Chinese chestnut and sawtooth s are both great picks for low maintenance that won't take 20 years to crop. However I do think both can be shaded out by other trees with Chinese be a little easier to be outgrown. So if you plant these two keep them protected from deer and eliminate compatition around them.
For fruit trees your best and easiest bet is pears no question. Avoid Bartlett because it will die from fireblight. If you wanna keep things simple you can wait til your Lowe's, home depot, Walmart, etc. Puts there trees on sale late spring/fall and pick up keiffer, Ayers, and Moonglow pretty cheap. If you want to expand your drop times beyond this the wildlife group has great disease resistant pears you can order bareroot.
Apples and crabapples can be fairly low maintenance or so I've been told if you pick the right varieties and do a little pruning each year. Examples of good varieties include Arkansas Black, Yates, pricilla, Terry winter, Kinnairds Choice, bevans favorite, dolgo crab, Kerr crab, chestnut crab, to name a few.
All these varieties can be ordered online from varies nurseries such as the wildlife group, Cummins, century farms, big horse Creek farms which are some I have used and had good success growing their trees.
The next thing you may want to think about is rootstock. In my opinion the three best apple rootstock for a wildlife planting are either m111, b118, or standard size rootstock such as Anatova. 99% of what we've planted are on Anatova or b118 because they are the biggest tree yielding rootstocks and both do well in sandy soils. M111 will still produce a big free standing tree and is supposed to do well in heavier soils. For pears I've used ohxf97 when grafting which is supposed to make a standard size pear tree though ohxf87 I believe yields 80% of standard and is also offered pretty regularly.
