Welcome to the forum. There is a lot of value in buying the RIGHT used garden tractor but there are often things that will have to be fixed on a used machine, often minor but sometimes major. Assuming as a newbie you don't want to deal with that, then lets think new for a minute.
The Husqvarna you speak of is made in the same factory as the Craftsmans, so look and see which has better specifications or features you like at that price point and buy which ever model it is. They share many components and will share attachments, baggers, etc as well. The new John Deeres in this price range aren't going to be better than anything else in quality, and I think you will spend $100-200 for the paint, although you'll get more of that back if you sell it later.
I am a little concerned about the hydro and your hills, but not enough to recommend against it. My hydro transmission is one of the best things about my Craftsman Pro, I would never go back to gear drive after using the hydro, it's way too convenient. I like the foot pedal drive, but many others like the fender control, that's personal preference. I like having my hands free for dealing with attachments.
In this price range you should be able to get:
42-50" deck, maybe even 54" but that takes more hp to run
15-24hp engine (probably a B&S Intek or ELS, or Kohler Courage or Command)
a LAWN tractor hydro transmission (NO ground engagement, light towing)
a lightweight frame, but look for one that's welded
cast iron front axle, don't buy the stamped steel axle Ariens or Troy-built
3+ gallon gas tank
a nice, cushy, sliding seat
Cruise control (useless feature)
Things you probably/definitely won't get at $1500
Electric PTO (I would pay $100 more for this feature, some don't like it)
Power deck lift
Ground engaging transmission
A zero turn mower of any type
Shaft drive (thousands more)
One more thing. If you buy a member of the Husqvarna/Craftsman/Poulan/Ariens group, or a JD, there will be lots of used attachments out there to buy for them. Other brands will have less stuff on the used market. Buying used attachments is relatively safe because most of them don't have motors that could be trashed.
Good luck in your search. You can make your second tractor purchase a used one (once you start there's no turning back). Remember
when your done!