Gk 1001 rb 2 works well with my fEarfuls, I use the high freq side to run the horns. Rock solid amp for over six years, tons of hours, been worked hard, lived in the trunk of the car in heat and cold, been dropped... Never a problem.
That said, if it died, I'd buy the Carvin BX 1500, and not worry. I also use the Carvin HD 1500 power amp. I did have an issue with that amp, but Carvins service folks were quick to replace it. I like the BX 1500 eq better, and in an A/B test with the fEarfuls, the Carvin more than held its own against the GK, with more eq and tone options.
Almost any amp will sound better through the fEarfuls. Some amps might not fully utilize the cabs.
My advice: build your fEarful, and then audition amps. Of the three fEarfuls I've built, two 15/6/1 and a 12/6 cube, the 12/6 with no horn and the inexpensive alpha 6 mid is my most used cab. Huge bang for the buck, under 50 lb, and it fits in the trunk of a Corolla.
__________________ Powder Hound on Supermodels
Dingwall Club # 89
Stand back, I'm packing fEarfuls!