Sund Rock would be a waste of helium lol
Gas Blending
$1.25/cf for helium is actually pretty damn competitive at the moment.
There are a couple of decent 130~160ft range sites in hood canal. Flag pole, Rosie's Ravine and Pulali Point. The wreck of the general and dalco wall are both doable with AN/DP+ helium. PB4Y, Harpoon, Valient, and Dawn in Lake WA. None of those would be air dives to me (each for different reasons)
I haven't done an OC trimix dive in 5+years, I am exclusively CCR beyond rec depths at this point, sorry. I do bank 32% but only for single OC tanks and the rare occasion when I refill a bailout bottle. I use standard gases which are all 32% topoffs (25/25, 21/35, 18/45, 15/55, 12/65, and 10/70)
About the only thing the al80s are good for is rec dives and deco bottle IMO. 145cf of gas is not adequate at 150ft in Puget Sound or Lake WA. Most people I dive with use an 80 of 50% at your target cert level. SM 117s are fat and honesty annoying but maybe you'll like them. Most of my OC SM dives are on hp100s or lp85s, the 85s are the nicest SM tanks IMO but only if you shop is willing to actually fill them decently - which is rare around here.