I bought the Gitzo GK1580TQR5, including the totally useless Gitzo ballhead. That was the most compact (usable) tripod I could find for travel. I later (threw away the Gitzo head and) added the RRS BH-30 ballhead. I did not go for the smallest head, because I wanted a panning function. Very often when I travel I do multiple shots for stiching. That is close to impossible to do properly, unless your head have a pan function. If you don't need that, I'm sure you'll be happy with the BH-25.
Some say that the BH-30 is to big fot that tiny tripod, but that is not correct. The only issue being that one of the legs is less than 1cm off its optimal position when folded. I highly recommend this combination, provided you don't load it with anything bigger than the 70-200 f2.8L IS II.