[sparkyboy22]

Added the xfactory sellers that had sites I could work with last night so a few new shops added. I cant remember which ones as I was a bit tired!

It's certainly possible to do this for any type of product that has specialist sellers with websites that sell the products.
Mountain bikes wouldn't be an issue as far as I can see.
The difficulty is that it takes me around 30-40 minutes to add each new shop and test to make sure its working properly.
I don't have the time at the moment to commit a couple of days to setting up a new one.

Maybe in the future, or if you want to do one yourself I'd be happy to let you know the setup I have so you can get started.