That pet place has wild type chromides and bumblebees at least, and they carry fig 8s but are out of stock. My personal history with that shop is good. They care about their livestock, and the fish came packed very well and both arrived alive. I'm not sure if they still have it, but they had a promotion where they had priority shipping (guaranteed to you before 10:30 am the day after shipping) free. They might not guarantee your fish if they will be exposed to more than 90 degrees F though. They will hold your order until weather is good, or you can tell them to go ahead, and waive your guarantee. If you contact them and ask for anything inparticular, they attempt (but do not guarantee) to get what you want, like a shy puffer or a mix of male and female chromides. I asked for a pair of chromides and it looks like they may have succeeded-no one's dead at least.
Regarding stocking for a 55g I'd start with mabye 1 puffer as they are territorial and dirty, 4 chromides, and about as many bumblebees as you think you can handle. Fig8s have a history of ignoring BBGs, and chromides are fast and large enough that they might be able to coexist with a fig8 decently well. I'm a bit concerned that chromides might try to eat the BBGs, but I have nothing particularly to back that up. Everyone is territorial here, but the BBGs will stick to the bottom, and each of the larger fish will have 11g to themselves, so it might just work out (assuming you get a decently docile fig8 and enough places for everyone to hide).
How are you going to cycle the tank? For a fish-in cycle you want about 1 inch of fish for 10 g of tank water. If you order all your fish at once you will probably have to order more later anyway because several will die. I know chromides are sensative, so for cycling get the puffer or the BBGs first. I'm not sure how tolerant puffers are of cycling conditions, but he packs enough of a bioload alone that you shouldn't need more fish. BBGs however are a below average bioload, so while it might take a while and require more fish, it would certainly be safer. Not sure how BBGs handle ammonia/nitrite either. You might just want to buy some mollies, they are reputable cyclers and it would be hard to find a local petstore that didn't have any. If you wanted to keep them the only potential risk would be with the fig8, but the fig8 is a risk anyway. Otherwise, just return them shortly after you get your new fish (don't expect any money back). You will still probably get a minicycle if you don't adjust the bioload slowly, however. So really, you might not save any money by buying all your fish at once, since you risk fatalities by doing it all at once. If you are doing a fishless cycle, never mind any of this.
I'm also worried because BBGs have a reputation for being fussy eaters, and fig8s/chromides are anything but fussy. You will need to have a plan for feeding them should the puffers and chromides gobble all the food before it gets down to the gobies.
