1) Phillipe has some of the best gargs in the world, and I wouldn't hesitate to purchase from him. I've also gotta give a shout out to Supremegecko.com, great people with great geckos. They do a lot of shows in the midwest and I've purchased two cresteds from them, always great for a chat

2) I wouldn't even house female gargs together. Even though gargs do regenerate tails, they are particularly known to eat the tails off of tank-mates (even females may do this). If you want to try it, I'd give them a cage at least 2 feet tall and at least 2 feet wide.

3) I use the Repashy CGD for 100% of my feeding needs for my crested and gargoyle geckos. Essentially it is a dry powder, you mix ~2 parts water to 1 part powder by volume, just stir it all together and put it in a feeding dish. The idea is that it represents the rotten fruit that the geckos typically eat in the wild. I use smooth ceramic dishes so that I can clean them easily. I usually feed a teaspoon to each gecko two or three times a week, I just leave the food in for about 12 hours overnight, and then remove the dishes and wash them.