I understand your rationales, but it is still a bit unwise to attempt an ocean crossing in an unsuitable vessel. I'd agree with Cam's assessment of this particular boat.
Since you expect to get a "good deal" in the American market, perhaps you'll have enough left over to arrange to ship the boat to the UK as deck cargo. Investigate that angle, and keep in mind that sailing across the Atlantic is not "free" either. There are real costs in gear and provisioning, and hidden costs in your time involved in the crossing. The net difference in real terms may not be so much, especially if you consider what might not go well on a 1st crossing in a boat not meant for such voyaging.
Also a trip like that may well put your "reluctantly sailing" wife off permanently should you convince her to join you on this venture.