It looks like you have a ton of great ideas! Here's one I saw on T.V.
I was watching Talk of the Town today, and they had a neat idea for Mother's Day. Meryl Rose (one of the hosts) and Ms. Cheap (from the Tennessean) were at the Beauty Institute in the Cool Springs area. Apparently, you can get spa services and stuff like haircut and style, manicures, pedicures, etc. for very cheap there because the services are performed by students there at the Institute. The work they showed on T.V. was very good quality spa treatments. Check it out at News Channel 5's website.
My mom loves gardening, and she says everytime she looks at one of her plants, she thinks of the giver, which is us, her daughters. Maybe your Mom would like a similar gift.
I hope you find the perfect present!