A few thoughts:
The Blackjack is a fine ride and Metro Boating is the largest dealer in the country for them. Check with George Haydel - good people there. Yamaha /Merc dealership.
Also, the old SeaPro design, now Triton Bay Explorer line, is an excellent performer
http://www.tritonboats.com/boat/336.aspx
Call the guys at LMC in Houston - they are the largest Triton dealer in the country and also a Haynie dealer. David and Jeff and the LMC team are very good to deal with too - Yamaha / Merc dealer.
http://www.lmcboats.com/
The motor technology is very good today and hard to go wrong. I ran V6 Mercs with nearly zero issues (one motor had coil issues) from 1979 through 2010 - my last two motors have been the 250 SHO and flawless so far.