Dont' bother with those jacuzzi bath tubs, especially the cheaper ones.
We put one of these in when we built our current house, and even before we got a real hot tub, we never used the whirlpool tub.
For starters, you need to fill the tub up from your water heater, and any decent sized tub will drain your hot water tank. From there, the water will cool off as you soak. Lower priced tubs do not heat the water, ours doesn't. It only has two whirlpool jets, which do a nice job of swirling the water around, but not even close to a real spa.
You might need to construct a base for the tub, and you'll need a GFI outlet under the cabinet to plug into.
Totally not worth the effort- put the money toward your spa fund instead.
If you do decide to put one in, you for sure want to measure the doorway to see if you can get the tub in there. Depending on your current setup, this $600 tub could end up costing a couple grand, easy, unless you can do all demolition, reconstruction, and electrical yourselved.