Question best low budget wireless mouse for using on bed/couch?

There are no mice that will work correctly, or well at all, on a couch or bed. You need some kind of flat surface that is at least semi-solid, for the optical sensors in ANY mouse to work correctly. Once you have that, any of those mice will work fine but I really doubt you'll find any mice that don't have separate right and left buttons. I've never seen one except track balls that have both buttons in one.