If it were me and you are going to go into large lakes (don't know what you consider large) I would go for at least a 16ft Deep Vee Aluminum.

I also prefer a tiller engine on a boat that size. The extra space without the console is nice.

I have a Crestliner Canadian 14ft that I bring into pretty large lakes on a few times a year. It's a deep vee and handles very well for its size...I have had a few scary moments when the weather went bad.

Most of the water I fish a smaller boat is better so that was a trade off.

http://www.crestliner.com/kodiak-aluminum-boat-16/

Something like this would be nice and you can go the tiller route...I know this appears to be out of the price range but something like it can be picked up for a decent price used.





ETA: Here's a few pics of my little 14 with the small engine on it for the restricted lakes (under 10hp) that I fish.

It's rated for a 40hp but moves great with a 25hp when used.

The first two (with the older Mercs) have issues with rotten wiring on the motor. The factory wiring was rubber coated and dries out over time. The insulation falls off and the wires either corrode away or short together. Look closely at the wiring on those motors, especially where it goes to the stator located under the flywheel.
The older OMC's (Johnson/Evinrudes) especially the "cross flow" style engines had carbon isuues and sticking rings causing cylinder scoring.
Old outboards all have their problems and in my experience, most people who buy an old outpowered boat from a private seller have had to put $$ into them pretty much right off the bat. May be minor servicing, but sometimes not and can get expensive fast.
Generally speaking, the aluminum hulls are lighter and draft less water.
Moral of the story is to lake test it before buying it. Buy what you can afford and both like, don't overpay! This is a buyers market! Asking $3000? offer $2300 cash contigent on lake test. If they give you the 'ol "I don't give free boat rides" line, offer to buy the gas.

Those two links are the same. The boat in that link looks ok, I just don't like Chrysler outboards...at all. I am working on one now and every one I have seen has issues. No problem liking Merc outboards..I do too I just mentioned their weaknesses with the wiring so you don't get an engine that needs $1000 worth of wiring/stator right off the bat.

Kinda hard to tell since the pics aren't that good, but it looks ok from what I can see. The motor looks like it is from the 80's with the tan color scheme (blue was the 70's and the red was the 60's IIRC) so it's newer than the others you posted. The wiring should be in better shape too. In his ad it says "40 horse Mercury motor runs great can start it here with the motor muffs" Red flag if he refuses to go for a lake test on your dime. Call him and ask him if he will after you go look at it in person. Make sure he knows you are serious and will pay (amount of your choice) with a lake test only. One pointer is to have you and your wife only to go see/test it. A seller will be reluctant to go for a lake test with kids in-tow.
IMO this is the best one you have posted so far..from the ads at least.
Good luck and let us know what happens!
ETA–– If you plan on skiing or pulling a tube fast, you will need more than 40hp. At the least with 40hp, you may need to re-prop with a lower pitch when skiing/tubing.