I ended up going with the 10lb tank...it ended up fitting with a few inches of clearance. That was what I was hoping to do all along and I'm glad it actually fit. Plus in the beginning at least, it will be better if it is right there so that I can monitor it and make sure it is working (or more likely, that I set it up right). In the future maybe I will try a 20lb and run a long line, but for now this works for me. Thanks for all the suggestions.