What's your budget? You are going to get what you pay for, and I would suggest making your group at least 6 people if not 8 so that you don't get party hunted with people you don't know. Keep in mind that what you see on Youtube isn't reality. If you shoot a handful of birds per gun per day on average you are doing well, meaning if a group of 6 shoots 30-40 birds per day they have done very well. Yes, there will be banger days but there will also be garbage days. Plan to hunt at least 3 days if not more. Spring weather sucks...and depending on the snow line you could be in southern Missouri or North Dakota in the span of just a few weeks. There are literally 100's of snow goose guides, and all of them have a trailer full of silosocks and an e-caller. Almost all of them will say "I follow the birds" and "We put 'em right at your feet" and such. They have to say such things....remember that. It's a dog eat dog world out there.
Be prepared to move decoy spreads, shoot LONG and TALL shots, and clean your gun every night because that Missouri/Kansas mud ain't no joke. Ask what type of blinds are used. Ask for past client contact information. Use whatever resources you have to gather as much information as you can prior to booking.
The more "cushy" you choose the more you are going to spend but the less you are going to have to help. The less you pay the more likely you are to be part of the hunt in a much larger way than you would normally anticipate.

I remember moving about 500 full bodies (with my friends) in Missouri to only have to move them all back about 90 minutes later. We shot 11 snows that evening. Yippeee...