I've been buying salmon at Costco.. the farm raised kind and I like it. Heck, I was commercial fisherman (salmon) for a few years and had nothing but the best pacific coast salmon available. I've never tried grilling Costco salmon or eating it any other way than smoked. I don't use any special brines.. just the simple rub with salt, brown sugar and sometimes a splash of soy sauce.
Typically, I use about a cup of sea salt or kosher salt, a half cup of sugar and a half cup of brown sugar. I'll dry the fillets using paper towels and rub on a mixture of dark molasses and soy.. about half and half. Sprinkle about half of the rub in the bottom of a stainless turkey roasting pan, place the fillets on t and sprinkle the other half on top of the fillets. Place it in the frig for 8-10 hours, flip the fillets and let it sit for another 8 hours. Take it out of the frig and rinse it well under cold water. Finally, I towel dry the fillets and place them on bread cooling racks. You could use the racks from your smoker and you will eliminate additional handling. I balance the racks on two edges of a couple of plates o the kitchen counter and turn a fan on them for a few hours until a pellical forms and transfer to the smoker. Typically, I'll use 1 oz of Apple or Alder for wood and set the smoker at 200ºF and let 'er rip till done. I haven't figured out how to upload a picture.. but, if you want to see my salmon, go to:
http://www.picturetrail.com/sfx/album/view/16070095