Formula, Baja, Fountain, Power Quest, are all boats that could be in your price range and year. All could get you to low to mid 70's. You start talking 80 and above your start talking big money.

Thats a good point 24ft and under you could do 20 but 26-30 will require a up to 30. I bought a 91 fountain twin 454 goes 70 3 years ago and was right at 30, now that same boat your still talking 25ish. 20 will probably not do it, but under 30 will.

Good Points
 

First off, I want to thank you guys for clearing up the budget, I wasn't really sure what that number would be and picked it on a limited search of what I thought was a good sample of boats. Looking back they were probably a little more "used" than I may want and were def. high hours.

One thing I hadn't considered was a smaller boat. So we went from a 19' cuddy to a 26' Nova II and saw little change in cockpit space,a minor change in speed and then a bigger cuddy/cabin. I hadn't thought of a 21-24' boat with enough power to run 70's and also wasn't sure if my running conditions would allow that for a comfortable ride. Any thoughts or opinions on this? Obviously I'm not running 70's with the family on board, but if my wife and I wanted to go out and run a bit would this be comfortable in this size boat? Our 19' was pretty rough riding at its 40's top speed.

a 21 ft boat going 70 would be insane and probably much the same on a 24 unless you got a better hull like in a powerquest or Baja. Remember you get what you pay for, all used boats have issues I dont care if it was bought yesterday or 20 years ago. Chances of a newer boat having issues should be less, but also with am older boat some issues might have been replaced already because of normal wear and tear where say a 5 year old boat could be coming up on some its natural life span repairs.

Personally for what you are talking I wouldnt go under 24ft. You could find a 24-27 boat all day for around 20 in a 90 or newer that goes 70 with something like a formula, checkmate, or baja. I would really set your goal for 70 as any higher than that you are talking above your budget and maybe your taste for maint cost

One thing to keep in mind you get towards 30ft in length you start talking needing a 3/4 ton truck/diesel to safely pull your boat.

I'd probably stay in the 25-27ft range. I mean true length. 27 fountain, 28 powerquest, 25AT, 25 Powerplay, 27 formula, 26 Hustler, 25 sunsation.