All The Hammer drinks (Heed, sustained Enegery, Perpetuem) use Maltodextrin as Fuels. Gu20 (cant remeber how to do a subscript) also does.
I like Perpetuem myslef, but I have a garbage gut. Granted find someone who stocks them can be challenge, but you can order direct (http://www.e-caps.com/) and they do sell sample packs.
PS. if you do decide to order direct, you get 15% off the first order if you are referred. (The existing customer also gets a cut). PM me if interested