Hey, John! I own this pack; bought it for the AT. While some may claim that with it being a frameless pack you shouldn't carry more than 25 lbs. in it, I think they're way wrong. When I first bought this a year ago I stuffed well over 50 lbs. of groceries in it (lol, had to try it out with something cuz it was the first piece of gear I bought after loosing all my former gear). For 50 lbs. worth of bulky weight it actually rode pretty well on that journey back to my apt. I have never used a bear cannister and honestly can't tell you that I've ever put my hands on one to tell you that I know for a fact I large cannister will fit. I will, however, say that if you pack properly then this would probably work well for you. The reason I say this is that you already mentioned strapping a bag and pad on the outside. This pack is GREAT for strapping/lashing gear to it. It does have the ice axe loops which work great for anything like that. It has the pad/bag loops on the bottom of the pack that you can use to lash your pad, sleeping bag to, if you wanna go old school. Another thing that makes this pack great for lashing is the compression straps on this pack are quite long. Ive seen people complain about this, but I think they are great. I lash all kinda stuff to this pack utilizing the extra length of the compressions straps (including my trekking poles, collapsible fishing rod and tackle box).
It sounds like you already have an idea what your weight will be and at 30 lbs. you defintely have a pack here that can handle that really well. Its hard to say not knowing your equipment, but one thing I found to help me out utilizing all the space in this pack is dry compression sacks such as the Sea to Summit Evac. My tent and sleeping bag used to take up a large portion of this bag's lower interior. I got rid of the tent's original sack and rolled it down real tightly to fit into a Sea to Summit 4 liter dry sak and then put my sleeping bag and extra clothes that wouldn't be worn thruout the day into the Evac sak and compressed it down to a tiny little ball. I pack the tent poles in their original sack towards the outside by the outer pocket, and down in between the compression sack and tent. Once again, without knowing your gear its hard for me to say, but after making a few packing adjustments I feel like my pack grew 1000 cubic inches. I'm pretty minimalist also, so take that into consideration if you are taking alot of clothing. Every ounce I pack counts towards more than one task. If you truly feel like you may need more than this pack has to offer in cu.in. I would try out the Golite Pinnacle if you're simply wanting to stay with the idea of a ultralight pack such as Golite. Man, I looked at alot of 'lightweight'' packs and none of them compared to Golite in terms of durability. After a year of pretty rough use it still looks brand new as if it never met a briar bush. Great pack! Give it a try and if you don't think it'll fit your gear, send it back to Backcountry and exchange it for a Golite Pinnacle. Pretty much the same pack except more interior. If you're not concerned about the bells and whistles on a pack and are looking for reasonable and durability as well as efficient system then one of the two are your best options IMHO!
ive never posted a pic on here before, but I'll go drag my buster out of the closet and pack my gear up in it and see if I can't get a shot of it along with my packing list to see if that can help you get a visual, also. If I can't get the picture up for some reason or get sidetracked by honeydos in the mean time then please forgive me. Hope this helps and good luck pack hunting!!! By the account you're packing a cannister I suppose a 'watch out for da bears' is in order, lol!