I wouldn’t recommend the Perception Dancer. It’s an older white water design with no deck lines, no bulkheads and not designed for speed or tracking.
Find some local outfitters - like the one you’re planning on taking lessons from - and ask if there are any boats for sale. As I said in the other thread, as fall approaches these outfitters start to sell boats off so they don’t have to carry them through the winter.
My wife is Nova Scotian and we get up there a couple of times a year. An outfitter we know there usually has a stock of Boreal Design (a Canadian company) Sedna models that he sells off every year and would be the perfect type of boat for you. That model is 15’ long and 23 1/4" wide. It has deck bungees as well as deck lines, two sealed compartments. While it comes with a rudder, my preference would be a skeg. It’s also poly which means it sells for half the cost of a composite boat.
There are many boats out there like this. Look for Current Designs, P&H, Wilderness Systems, Jackson, Necky, etc. You should be able to find a good used boat in this range for about $600-$800.
And, as @Rookie says, a fully swamped sea kayak will still float and will allow you to get back in but you’ll want to pump it out just as soon as you can. A paddle float and a hand pump are pretty much mandatory accessories especially if you’re paddling solo.