Welcome aboard
You can go to fourwinns.net and look at the brochures/specs. Outside of about 1' difference in length, I think the H200 has a straight bench in the back (sunsport seating) and the H210 has U-shaped seating. My suggestion is to test them and have them looked at by a mechanic, then buy the better of the two. If they are pretty equal, get the bigger boat
Either boat will work though. My H200 seats 8 pretty comfortably and has no issues with that many people in the boat. I do have the 5.7L vs the 5.0L. I'm not sure how much difference the smaller engine would affect performance. You can always get a different prop to suit your needs though.As far as swimplatform goes, do a quick search here. I think they are running around $1800, give or take, for factory and after market. I don't recall if that includes shipping or not though.