Make sure you have 50 amp service, (my tub actually required 60 amp but the norm is 50 amp). I would ask the seller as-well what it requires, and make sure the seller has the manual for the tub.
Make sure you have a plan on getting it back there (don't want to rent a crane).
If its just you and your wife using the tub, then get the spa frog for your water treatment, as it is SIMPLE. Get a bottle of powder shock and use a tablespoon once a week depending on use. (I've use the other chemicals, such as baqua spa, bromine, it seems you need to be a scientist to get these right. Spa frog you just put it in and forget about it for 4 months).
Make sure the tub has a way to drain the water, and position the drain in a way that it is easy access.
Lastly, If I were to do it again, I'd buy a used one. I see them all the time, and they are usually a pretty good deal, just be picky and be prepared to pay a little more for the one you want (You'll still save a grip of money over a new one).
PS,
Lovin Evolution, Lovin my new Sinisters, in fact I had to ditch my Klim helmet and took the S2's with me so I could pick out a helmet based on the fit of the goggles.