We've stayed at both the Premier Inn and the Ibis on Cold Bath Road. Both fit your bill. Both are (comparatively) inexpensive. Of the two the Premier Inn is the nicer, but the Ibis is perfectly acceptable for a one night stay.
Both are served by the Hoppa shuttle buses but frankly if there's two of you or more, then a taxi would be almost as cheap, and probably quicker. I was a bit horrified by how much the bus tickets were for such a comparatively short trip, but then again, I thought the taxi fare was a bit steep some years ago when we took one to our hotel, which made us investigate the bus services. In the end we determined bus was cheaper, taxi more convenient. Depends what your priorities are I suppose!
You can Google the current bus schedules, and possibly the fares.
Have a great trip!
Ian