I can't personally speak to actual gender therapist but can say a little something about a therapist that "deals with transsexual issues". In the case of mine, I'd call him TG friendly and has some exposure that I kow of to other TGs through my group. No way would I consider him a gender therapist. OK if your goal is a clearance letter for hormones. Not too OK in helping you sort out or question who you are.
Living in a rural area my pickings are slim to none. My TG group and therapist are 90 miles away. The closest "gender therapists" are in either Washington DC, Baltimore, Phillidelphia, or Pittsburgh. All of which are like 3 hours away just to get into town.
I guess the choice comes down to your goals. Mine was primarily to help me through life issues who was at least aware of some of the baggage a TG accumulated through life. I had no goal of transitioning. Just not wanting to see my life explode once again over the not so good ways I developed to handle being TG.