Hi! I can comment on a few of the suggestions you have (including a few new ones to consider).
- Erika Volchik is nice, but very young and green for a trainer. I know people that like her. Probably great for beginners (not sure of your level).
- Susann Regalmuto is wonderful. She's kind (to humans and horses), knows her stuff, and is a consummate professional. I don't know if she has a lesson horse available at the moment but you should definitely ask. I have trained with her and would recommend her in a heartbeat. Very easy and pleasant to work with. One of the few trainers I trust to ride and care for my horse without reservation when I would go out of town on an extended vacation or whatever.
- Someone not on your list, but you should consider is Pat Lincourt at the Paddock. She's primarily a jumper trainer, but is also a USDF L graduate and has competed through PSG. She has excellent dressage training, and competes in dressage (I think she's trying for her Gold medal), and is another kind and easy to work with personality. Probably has lesson horses.
- Claudia Roberts (I think at middle ranch now) is fine. Lots of people like her. I think she's generally not as good as she thinks she is.
- Nina Winternheimer (sp) is probably the most competitive professional in that area. She's an excellent rider, but you'd be looking at a more competitive program.
- Laas and Ulf (Middle Ranch) also old, competent trainers in the area. Probably don't have lesson horses but can always ask.