I think Roger pretty much covered it. I have been by Squamish a couple of times on the way to Whistler to ski - windy and rough, but it looks like a great sailing area. On a 15-25 day in that water, the 144 will be way too large to learn much, unless you can find a protected area without the big chop, but then you will have puffy winds which will also be difficult.
I weigh 79 kg and even though you think you need the 144, you shouldn't have any problem uphauling the 133 or even the 122. The 111 will be a lot more tricky at first, but very doable in time.
Roger - if you haven't seen Squamish, "river" is a bit of an understatement. There is a huge bay with good sized mountains on each side that the river feeds, and wind gets sucked up/down the river/bay much like the gorge. I am trying to remember the wind direction, but I clearly remember tons of big white caps for miles and miles.
Formula 160; iSonic 111; HiFly Move 105; Tiga 263; '85 Mistral Superlight.
Maui Sails TR 11.0; 9.2; 8.4; 7.6; 6.6; Maui Sails Switch 6.0; 5.2; Maui Sails Global 4.5; 4.0.