I've never used that smoker, so I can't help you there.
But I have cedar planked salmon several times in an ordinary gas grill and it is fantastic. I've used a marinade that I made up on the fly consisting of diluted red wine vinegar, lemon juice, thyme and cracked black pepper. I'd give you a recipe but I don't use recipes on stuff like that. I just smell them as I go until I think it's where I want it. Let the fish sit in the marinade for about 30 to 45 min (much longer than that and you can get significant acid cooking from the vinegar). Then plop it on a cedar plank and onto the grill at medium temps with the hood down. I just kind of eyeball it and poke it occasionally until it's at the consistency I like. There's some controversy over whether soaking the planks before cooking makes a difference or not. I won't call myself an expert in that, but I usually don't soak mine and have never been disappointed with the results.
This is also fantastic with tilapia.
Also critical is salmon selection, IMO. Personally I'm not crazy about farmed salmon. It tends to be considerably fattier than wild salmon because of how they feed them, which I don't like. I also have some ecological concerns with farming operations, but I won't hop on that soap box. If you're particular like I am, check the label. They're supposed to identify it as farm raised, but they frequently do not. If it is labeled as Atlantic Salmon, it is farm raised even if they don't say so. There are no commercially viable wild Atlantic Salmon populations left. And Atlantic Salmon grow much faster than their Pacific cousins do, so they are the ones that wind up being farmed for profitability reasons. To the best of my knowledge nobody really farms the Pacific species (sockeye/red, coho/silver, chinook/king, humpback/pink) because it's tough to turn a profit doing it. Anyway, I'm a little uptight about this so take my views with a grain of salt. -Kosher salt, preferably because I like the texture.
I personally prefer sockeye if you can find it. It should start showing up in stores soon because sockeyes start their run sometime in May to June, I think. I got a Copper River sockeye at Costco a few years ago that I cedar planked with that the marinade I mentioned above while on a house boat on Lake Powell. We ate as the sun was setting and the temps dropped down to mid-80s. If that's not what Heaven is like, I'm not sure I want to go.
Of course wild salmon is seasonal if you want it fresh, so that's the trade off.
Anyway, just my $0.02.