Replying to Powder Ski Size Question (with details)

Hey guys so I found a killer deal for some pow sticks online (Surface New Life's 2013 ) for only 263$ say whaaaat? I was just about to make an impulsive buy but I needa be smart here....

They come in 174 and 184... I'm 5'11" about 150 pounds and I'll say i'm pretty experienced. I've been on some Atomic Panic 181's and they've been fine for me a little tight in the trees though. Would 174 be too small on me especially in the powder? (I'm only gonna put on more weight through the years)...

I'll be spending most my time in-bounds glades and cliffs, although I'm venturing out to the sidecountry more and more as I get the gear and experience.. But I tend to stay on the most challenging lifts. Does this mean I should go with the 184's?

Also I'll prob just throw on my old salomon bindings, but would an AT setup and skins work on the New Life's? I'm new to all that so I'd definitely do my research before I go balls out but any advice really helps me out.. Cheers guys! Stoked for the season!!