Try the viaMichelin website. it lists just about every hotel you will need, along with information as to whether the hotel has a garage. Pick one, try it. After all, that is how most folk found the hotels they like in the first place. Also, have a read through some of the trip reports to see if anything catches your eye.
'Biker friendly' is a concept that does not exist in France (or even in the UK), patrons like customers whether they came on a motorcycle, horse, car or walked in the door. Behave like a yob and they will treat you like a yob..... see 'The Grey One's' thread if you have any doubt that 'bikers' never behave like boorish yobs.