Hi
A good place to start is Max's excellent sib advice thread over on Inflatable boats:
http://www.rib.net/forum/f50/which-s...sib-62208.html
To try and answer your questions directly. The Prowave is a standard generic Chinese sib, no better or worse than any of the others. I will say that it looks to be well speced for a reasonable price. But the general advice is always to buy a brand name over a little known boat. I would think the Honwave T38 is the closest to that boat and it will be worth a lot more used than the Prowave ever will.
Selva have never been popular in the UK, the 2 strokes were plagued with problems and are very unloved on the used market. But the company do seem to have turned a corner and I believe they have now teamed up with Yamaha to produce some of the new engines. The specs for that engine look great and the weight is really good for a 4 stroke.
However most of us prefer 2 strokes on sibs, they are lighter, rev better and just seem to match sibs better.
Is it a good combination as a starter boat ? Yep, its not bad, the boat will probably plane with 2 up and do 15-20 kts. Its big enough to feel safe but is transportable thanks to the airfloor and relativly light weight engine. But be warned, speed is addictive and you will be after a bigger engine sooner rather than later