First, good to hear both you and your wife have experience running boats and are comfortable with the whole concept, that's a great start. Second, I'm pretty sure that I've had everything on Slickcraft's list above in my boat at one point or another.
On the 3 foot question, there's more to that than just length. Our 19 was an older outboard boat with an almost flat bottom at the transom. It would plane easily with modest power but you had to slow down a lot when it got rough, going through boat wakes and so on. The 22 has a true deep V hull design (23 degree "deadrise" angle at the transom" that helps a lot on a choppy day. Add a V8 engine low in the hull along with a 70 gallon gas tank and it's a completely different boat.
On the subject of deadrise, a lot of newer boats have shallower V angles often referred to as a modified V hull. The relatively flatter bottom helps with getting the boat on plane and they're often faster than a similar deep V boat with the same power. I think this has a lot to do with the popularity of 25, 27 foot and larger boats for use on the lake; that must size / weight range needed to get a good ride from the typical modified V hull. Bear in mind when I was a kid up here in the 70's a 19 foot boat was considered "big".
If you can find a place on Sleepers or the sheltered sides of Rattlesnake or Bear, you can probably get away with an 18 foot bow rider for a while. There's no way I'd personally want to try that out on the Broads side of Rattlesnake though, maybe some of those members that have experience will chime in on that.
If you're nearby, I think you'll understand a little more in a few weeks when we get some strong sustained WNW winds and you can get a look out to the Broads. Things can get pretty "sporty" considering this is an inland lake...
Good luck, you're asking all the right questions!