I haven't personally brewed it, but several people have tried and loved rlbois's Dual Spires Black Lodge Ale
; it's dark but not too dark, and will probably suit your tastes. It's also extract-only, using sorghum extract, rice syrup, candi syrup, molasses, and malto-dextrin, all of which you can get from High Gravity Brew
(except for the molasses, but you can get that at any grocery store). I'd say it's probably your best bet as a first GF beer.