I have a 93 Chaparral 19' bowrider and love it - its got a soft floor, but it did 4 years ago when we traded for it and its still holding up. it has a 4.3 V6 in it... runs well to this day and has been a blast - will run near 50 mph on calm water with the family and gear.
It seems the basics have been covered in this thread... and if you're buying from a buddy who's had to put lots of $$$ into the boat, and now its running well, then you know what you're getting... really not much to look into.
just remember, the shorter the boat - the rougher the ride on medium to larger lakes.. they just don't cut through waves like the larger boats do.. that is unless you get an older boat with a Deep V hull.. those suckers cut like a knife thru butter.
Outboards are nice because they can be run all year long without having to winterize them... but they do get in the way of having a swim platform or general entry into the boat from the rear..
I love our boat and do'nt regret the purchase one bit... just bought a bimini top for it this week, so going to be able to get out during the middle of the day and not get burned to a crisp!
all we've done to our boat in the years we've had it is get it winterized every winter which includes draining the engine of any water, fogging the cylinders, and changing the lower unit gear oil, changing the engine oil and filter, and 2 new batteries