The Sovereign was / is a very popular model in mid sized "6 person" hot tubs (hot tub sizing is like tent sizing, take the advertised number and divide by 2 for comfortable fit) so 3-4 people in the real world. (note it looks like there were 2 Sovereign's in 2002 the regular and a slightly bigger Limited edition, models I and ILE, the regular Sovereign is 120/240 convertible, but it looks like the ILE is 240V only). It also looks like the ILE is a mirror image layout to the regular sovereign. For features it comes with the Hot Spring single Moto-Massage seat, as well as a fair variety, later Hot Spring tubs after about 2005 tend to have the dual Moto-Massage with 2 sets of moving jets, I can't say much here as my tub also has the single Moto-Massage seat, some people love them some don't I am in between. Controller will be the first generation of the IQ-2020, features will tend to be basic by modern standards, by 2002 it should have LED main light (my 1998 still had a 75W incandescent bulb), but will be blue only not color changing as that did not come out until 2005 or so. 2002 should also probably be the Endurol egg shell looking tub, these are much more durable than any tub built today, just don't have that pearlescent smooth finish everyone seems to want. If you do end up getting it and having to run 240V wiring be aware the wiring requirement for many of the Hot Spring brand tubs is different than many other brands as they require a neutral wire in addition to the 2 hots.
Ike
p.s. note if the jets, spinners jets, moto-massage cover plate, etc are gray or beige, as beige has been discontinued a couple of years ago, but can still be found as new old stock on ebay some times, but will only get harder as time goes by. Most /all parts are still available.