Well, first of all velillen, I'd recommend getting that small gap under the porch blocked off. Else, you're going to have a family of skunks/feral cats/etc. moving in.
I think most of the stuff was covered - you want the mowing deck to be HEAVY. Otherwise, the thing is going to rust through eventually. (my mowing deck is around 40 years old & solid.)
One thing I dispute that was mentioned in the thread - someone said the more horsepower, the better. WTF for? Mine is 12HP and is capable of operating a plow, a rototiller attachment, a snowblower attachment, etc. Higher horsepower models of riding mowers are like megapixels in cameras. People believe that higher is necessarily better. What they're overlooking is that they're making a lot of the other components cheaper to compensate on the total cost. "Well, brand A has a 20HP for $1999, and brand B has a 24HP for $1989. Brand B is clearly the better bargain." Wrong, but that's how people shop. 12HP is plenty for a 48" deck. A real tractor, one capable of operating a brush hog and doing multiple acres in very little time, can be as low as 24HP. 24 in a riding mower is overkill.