In addition to the tires and saddle, I'd perhaps add some bar ends if you don't already have them on the bike, so you can have a variety of hand positions. Eight miles on a mtb can be pretty hard on your wrists.
Ride this bike into the ground, and when your kids move on to the bus, reward yourself with something new. You'll have a better idea then, also, of what works for you and what doesn't at that point...which will help make you a better shopper for a new ride.