Don't worry about "Aqua History", the boat hull really only has true meaning to the one that owns it. It is indeed a model that we (I) haven't seen but that doesn't, in itself make it worth more than what anyone is willing to pay for it.
I'm not sure what your idea of a "deck boat" is. Can you compare an Aqua model to what you are looking for because if not, then you need to shop another type/brand hull. That is your best bang for the buck in getting to where you want to be.
Compromise? You bet. What boat isn't?
Knowing how you will use your boat over time is the most important element in deciding the type hull/model you will purchase.Don't waste your time and money if it's not what you want. Good luck.
A big NO would be the answer If you were to see the way I cut and re-fashioned my 82 19-6 and no one gave me any grief or hard time, just made the boat what I needed it to be, maintained the hull( exception being adding a anchor pulpit) and made the rest to suit my needs.. The rebuild part will try you at times but with some help and rebuild info gotten off of here you should be ok to go, if that's the route you want to take.
Go buy this for $1500 and start off with a boat that's more like what you want in the end:http://www.ebay.com/itm/22FT-HARRIS-DEC ... Motorboats
OK,You are limited with the existing beam as to how "rounded" you can make it. Of course you can remove the cap and redesign another or......You could keep the cap, remove the port side console and put a full bracket on back. You would have a "side console" model but you may need to re-rig for the bracket/platform due to control cable lengths. A full transom rebuild (could still remain open but raised to mount the bracket at the right height for the 25" shaft) to fully handle the larger motor and tie into the stringers. Back to back seating at the helm, cooler seating on the port side where you removed the console, retain the front seating, and possibly the rear jump seats should get you to 8 soles on board.Place the live well on the starboard side of the platform to keep as much cockpit space as possible and build in below deck storage on the port side under the above deck cooler/seating.Batteries moved to port side storage will need bigger cables but also help offset weight from bigger motor moved 26" to the rear.Nice project in my younger days but still $$$$$$$$. Good luck.Edit: Forget the bracket/platform and remove the rear jump seats (got to move batts now) and the splash well guard. This will give you more cockpit space and save you coin (wire is cheaper than a bracket).Use Gulp bait.
I make my living these days with costs estimates so I can't guess but I still do... First, assuming you're fairly close, double the bottom line for budget purposes. Marine ply is less costly if I remember correctly but the rebuild heads can chime in. Good tinned battery cable, properly sized with connections for same will run $300 more or less.Do you have hydraulic steering?Trailer OK (tires/springs/lights)?Seating?Electrical (wires/switches/lights)?Plumbing (pumps/thru hulls/hose)?Any additional/any electronics/VHF/stereo/GPS/sounder?Remember, no matter what anyone tells you, you need to go on the assumption that whenever you remove/repair/replace anything on an old hull, you will always find something else to repair/re-new/bitch about/spend MORE money to fix.Not a pessimist but rather a realist.Good luck.