Here are a couple of comments on the route. It seems that you have picked some of the nicest roads. The BC stretch from from your 12 to 18 (Golden, Revelstoke to Creston) is beautiful. It looks like you are going across a couple of ferries which make a nice break. The ferries run often in the summer and are free.
Revelstoke -- lunch on the picnic tables by the A&W, fast food or pack your own to avoid the tourist scene. Right by the bridge and train bridge.
Nakusp -- when you turn south, there is 30 minutes of straight fast road to the ferry and then a dead stop crossing on the Galena Bay ferry. You can usually get to the head of the line. This can be overloaded, they run 2 in summer, worst wait is about an hour. There is a point to walk out on and usually some one has a coffee shack set up. Then 30 minutes of heads-up but fast road to Nakusp. The Kuskanax lodge is the best place, on mainstreet. The beach is great. The hotsprings road (Nakusp Hot Springs) is about 8 miles but is paved now if it's cool enough to go to, the water is very hot, it is back towards the ferry just out of town. When you approach Nakusp you have to stay right and get off the highway bypass near the Esso, just stay right, the town is too small to get lost in, you go past a school and a copshop to get onto mainstreet by the lake.
Kaslo -- the road from Nakusp to New Denver is excellent. New Denver has a good motel in it just thru the 4 way stop on mainstreet, that cafe is the only place decent to eat...
The road from New Denver to Kaslo is the one I call "the Final Exam". Good pavement if they aren't working on it, but the curves are NOT engineered, the hairpins are for real, slow down and stay one with the road, easy to drift off, it's pretty. You will pass the ghost town of Sandon just out of New Denver, it is all dusty gravel and while it is interesting it is really SUV territory altho a bike can do it in dry weather. If it is rainy be aware the road used to puddle up.
In Kaslo the mainstreet is fun, the Mariner Hotel there should be done its reno's but I would not count on staying there. This is hippy funkytown. Walk down to the old paddlewheeler and cruise the shops. It is pretty much a one street town, the Langham centre has some crafty stuff in it. Be careful on the 50 kms from N Denver to Kaslo, this is the best bike road in BC for my money.
South of Kaslo is Mirror Lake which is the very best tenting/campsite. As for a tent site at the far end of the lake. It is off the road, the lake is swimming temperature, quiet usually. Also little cabins for rent if available and the weather craps out.
South of Mirror Lake is Ainsworth Hotsprings, stay at the Ainsworth Motel
http://www.ainsworthmotel.com/index.html Not, repeat not, the Hotsprings resort, expensive!. The hotspring has a U shaped cave you can go in and around in, alot of rules, not as hot as Nakusp, but the view is great and it is worth a stop and a relax. From there down to the Ferry at Crawford bay is good road with one wicked hairpin at Coffee Creek but you'll know it.
Crawford Bay BALFOUR -- good ferry service, cafe there, sandy beaches. Mellow scene and motels all along the way if you are at the end of a day.
Creston --You get off at Crawford Bay, the ferry traffic is a pain, the road needs patience to get to Creston, alot of almost but not quite places to pass. Best restaurant stop in Creston is as you come into town, the ABC restaurant on the right in a shopping centre, good grub and service, downtown is a struggle. Take in the fruit stands as you leave Creston headed back east.
More info about the Canadian side if you want. But the route looks excellent.
For the original request of accomodations, East Glacier has a number of spots from hostel to the grand lodge. We stayed in Jacobson's Cottages which were very good.
Have fun,
Jeff