In short, though, It seems as if most people who try heather ales use a Scottish ale as a base. Doesn't mean that's your only route. Perhaps use some heather and some hops in a standard english bitter?
BYO has a heather ale recipe on their website.
A commercial brand from Scotland that is sometimes available in US stores, Froach. I found Froach to be a nice malty Scottish ale with some floral aromas and flavors. Not nearly as different as I would expect.
I am planning on making something similar to the BYO recipe this winter using mugwort, sweet gale, and heather. Since the information on gruits is somewhat limited I plan on splitting a batch and doing a couple experiments with quantities.