I apologize for the long post, not sure if it is helpful, but wanted to make sure you are informed as much as possible when picking out a vessel.
I came from a similar background. Have some experience with Jet boats. Speedsters are definitely a great choice, especially for not having too much room in your context. For the supercharger concern, it depends on your setup. If you are going for a twin engine setup, getting NA engines, for the speedster's size and weight, NA engines are plenty for your needs. My neighbor has one, and with 310hp, it is plenty fast, generates enough thrust for tubing and accelerating like a jet boat should, overall fun, and don't have to deal with supercharger maintenance. Have been told doing maintenance yourself can be challenging, due to how the engine compartment is laid out.
If you are looking at something with a single engine, you will definitely need a supercharged engine to help compensate for weight. I had a Yamaha AR190, single engine, and that boat lasted a year before I sold it for a 210 Challenger SE. The issue I had with that was that with 4 adults, it worked alright, but tubing was difficult as every time the tube went off the wake, it would be enough to force the boat to turn. If you know for sure you will 2 adults and a child or a few, then one NA engine would suffice. But if you ever have more than 4 people on the boat, and then want to pull a 3 person tube as well, the engine will bog down.
Personally, I wanted plenty of room, as to why I got a challenger, and very much enjoy my twin supercharged setup to help with 10 people on board and still able to pull myself up when I want to slalom ski with all my friends. Even though I have 2x supercharged engines, top speed and performance are on par with a speedster 200 with twin NA engines.
When it comes to fun factor, SC motors are a lot of fun! They can generate quite a bit more thrust and get on plane faster and don't get bogged down easily with added weight and drag. That said, with 3-4 people, with SC engines, the boat will perform like you would expect from a jet ski.
Regarding SC rebuilds, there is a little more to it. There were several iterations of components for the SC rebuild kit. Any SC engines prior to '08 need to be rebuild ASAP, as they can lead to catastrophic failure if the SC fails. That was due to the washers bring ceramic and, being brittle, would rip apart into fragments right when it failed. Somewhere between '08 and a few years after, they changed to a titanium alloy, which was later improved to stainless steel, (what the service manager as the Seadoo dealer told me). That meant that as the SC washers began to wear, they would warp a bit and cause the clutch to slip and would give you more of a heads up to get the SC rebuild. Additionally, when the metal washers failed, they would break into a bunch of small pieces. With the new rebuilt kits, they are rated up to 200hrs and from what I understood, that depends based upon how aggressive the boat is drive. More specifically, the SC clutch gets worn out faster if the boat is jumped out of the water and air gets sucked into the water intake (or if the boat is turning and lists enough to suck in air on one side). Happening a couple of times isn't that bad, but it is more prevalent in jet skis. Even though the engines in the boat are very similar to the boat engines, the SC rebuild is 100hrs because of how often and easily the jet skis jump out of the water, otherwise they would be recommended at 200hrs since they use the same rebuild kit as the boats. If you are unsure if the previous owner has rebuilt the SC, and you ride test it and find it fine, would highly recommend rebuilding the SC soon after as preventative maintenance, or piece of mind.
Again, sorry for the long post. If you have any questions or want any clarifications to what I said, I would be glad to answer them as best as I can! I have very much enjoyed learning more about these boats and spend way more time then I should reading about them. That said, if you have any questions, regarding anything about these boats, feel free to ask!
