12’ kayaks are too small for the Great Lakes. Superior is serious water, with a potential for strong waves and currents, sudden storms and always water that is too cold for safe prolonged immersion – though warming trends have caused record surface temps this year, 70 is not that warm and the deeper water off shore is still bitterly cold. Today the lake was 46 degrees. Hydroskins or even a 4 mm wetsuit, will not protect you from that temperature . The longer kayaks will NOT hamper you on rivers and inland lakes and would give you the wider option of usage.
If you honestly intend to do coastal paddling eventually (and you should not attempt that until you have some instruction and have practiced getting back into the boats in deep water if capsized) you should be looking at 14’ minimum for the wife and kids and 15’ minimum for you. The Expression 15 is the only one in the Perception line that I would suggest for you. The largest Carolina is rated at 300 lbs and you are too close to that (plus gear) which can make the boat unstable. The Carolina 14 is also narrower by almost 3" which could be a too snug fit. You need the width extra 25 pounds of capacity of the 15’ boat. Honestly, for coastal use, at 16’ or 17’ would be more appropriate for your weight.
We usually recommend on here that used kayaks are the better way to get started and they are fairly common in the UP. Listed below are some I spotted in the “Yooper” section on Craigslist now.
Depending on the size of the 12 year old, this Tsunami SP (for up to 120 pounds) is a good buy and very sea worthy, though he might outgrow it quickly:
Another boat scaled for the 12 year old (unless he is big for his age), for only $250:
This Current Designs Willow would be good for the wife or teen:
Here’s a Carolina 14 for $450:
Another good one for you, a Prijon Kodiak, or the older boy if he takes to paddling on the big lake:
Another smaller Prijon in Ishpeming for $500, comes with a paddle:
I know some people prefer to just drive to a store and load up, but if you have the patience for buying used you can save a LOT of money and get a better bang for your buck. Also, when and if you want to change models and upgrade or just don’t want to paddle anymore (though that is hard for me to imagine!) you can get a higher proportion of your investment back by buying used. And often sellers will through in a decent paddle and even a PFD, which can save another couple of hundred at least.