I don't get the having to have someone that is specifically a "natural" trimmer. If a farrier is any good they should be able to keep horses barefoot with no problems, but also still have the ability to shoe a horse when/if needed. 99.9% of the barefoot/natural only trimmers I know of can't/won't/don't know how to properly apply shoes.
I would dearly love it if I could have a farrier that did both.
However, I live in an area where most horse people are extremely ignorant about the animals they care for. That goes for the trainers, the BO's, the farriers, and the general horse people.
For instance, the lady I used to board with, who used 3 separate farriers in the 2 years I boarded at her house, was told by all these farriers that it was acceptable for the horse to not be trimmed during the winter/spring (she fully believed them and she's been keeping horses for over 30 years...). According to them, that extra hoof "helps" pasture-kept horses function better with mud. They saw nothing wrong with leaving shoes on until the hoof grew out so much that the shoe fell off.
They also saw nothing wrong with never trimming a constantly foundering mare because "she's not ridden". They'd pull her out of the pasture, look at her seriously long, cracking hooves, and tell the owner that the mare was fine trim-wise but that thy could add some shoes to help with the cracking.
When I had one of those farriers check this hoof out (during their visit to the farm for another horse) because my mare seemed "off" on it, I was told that she could probably go another couple of weeks before being trimmed:
I didn't know any better at that point and I believed him.
Thankfully that was also about the time that I decided to find my own farrier/trimmer and happened to find a barefoot trimmer in my area (the one sane, really knowledgeable horse person I have ever met in my area). My trimmer doesn't do shoes. I'm sure she could (she used to be a "real" farrier) but she doesn't. My mare doesn't need shoes, ever, so it doesn't bother me. If I had needed shoes done, I wouldn't have chosen the trimmer I did, or I would switch to a farrier.
I completely agree that all farriers SHOULD be able and trained to do barefoot trims but in my area, that's not the case. Because of the experience I've had, I'm nervous recommending farriers for barefoot work. I know that some/most farriers are much better than the ones we have around here, I'm just still nervous about it. Hopefully you can understand that.
Really, OP, if your farrier is competent, he/she should be able to do a good barefoot trim.