I have bought two sugar gliders from Helen's Little Critters and the only problem I have had was some of the information I was given was kind of iffy. The breeder is very helpful and since I live really close I can stop by when I need help. I have seen where her sugar gliders are and they are not in small cages or in poor living conditions. (and it's not like she knew I was coming and had plenty of time; I went over there because my first glider had gotten diarrhea and I only gave her around a 5 minute time frame from when I called and upon arriving) She is USDA approved, though as of right now, for some reason the inspector hasn't been out to check her out and it has been almost 15 months since the last inspection. The only problems I had were when she gave me the baby food for a treat (gerber baby stage 1 beef and beef broth; which is high in phosphorous and gave my glider the diarrhea because I gave him so much), the fact that she neuters the gliders when they are awake; she says that she does not want to risk the chance of them just not waking up from being put under anesthesia (even large animals like dogs can not be under for more than around an hour and sugar gliders are MUCH smaller; I personally think this is understandable), and the vet she told me to take my glider to does see "pocket pets", but not sugar gliders. (she helped me find another vet and told us that she actually only takes her gliders into the other vet's office for a check up and she hasn't had a glider that was actually ill to take to them)
She starts the gliders on pellet diets when you first get them but encourages you to feed them many fruits, veggies and sources of protein (like eggs or chicken) as well and to try other diets if your do not think hers is enough. (She had in fact suggested I try mine on one of the diets like the Priscilla's diet when I told her I was worried that they weren't getting enough of the nutrients they need.)