Probably a Chicago Hardy, which is a great fig for colder climates that is actually a pretty reliable fruiter!

I'd use a good quality, durable potting mix if you only plan to keep in the pot for a season or so. If you anticipate a longer period in the container, use the gritty mix.

And wait to see how big the thing is when you get it and select a pot size then. Start out small - just enough to accommodate the root ball now or slightly larger - and pot up when necessary. While the Chicago Hardy IS hardy in colder climates in the ground, it won't be in a container and you will need to move it in for winter protection. Big, heavy pots are harder to move, so keep that in mind.

I planted figs that sounds like will be the size you will receive and put them in 5 gallon buckets. Figs have a vigorous root system and will fill out the size of container pretty fast. I will leave them in the five gallon bucket this year but it looks like I will have to pot up next year. If you put them in too small a pot it will quickly become root bound. However, I do live in zone 9a and things grow bigger here due to longer growing season.

Well I do have a hand-truck I use to haul in and out my big horseradish barrels from outdoors to overwinter in my solarium every year. So moving a five gallon bucket or even the bigger party bucket isn't that harsh of a deal.