On those bikes I'd think you'd be okay assuming you are okay on the trails. I've not looked at the route for a couple of years but the following bits may pose a challenge
1 - there is a small loop NE of Machynllech. That can be tricky but an easily be missed out (it's v badly chewed up)
2 - Bwlch y Rhiwgr (which is the mountain pass to the north of Barmouth) can also be tricky, though S to N is probably the easier way.
I've only ever camped when I've done it so can't suggest much in the way of accommodation. There's quite a few biker friendly places in Rhayader, and there;s also the Bikers Retreat in Dolgellau which is meant to be good.
Enjoy. It's a good route.