Figured I'd mention Mongo, it seems close to what you're after;
48V 15AH V2.5 LiFePO4 Battery Pack
Magic Pie 2 - Rear - 26 Inch - Golden Motor Canada
15ah LiFePO4 & MP2 hub on a Mongoose Snarl, good for just about 30mph for 30 miles (no assist). Two years so far as an all-season daily rider & commuter, somewhere between seven & ten thousand miles on it w/no issues - except the throttle I busted flipping it & the tires I've used up riding it ofc
Regardless of what motor chosen, do not get a "kit" with the battery included from the motor retailer, they're way over priced & over rated for what amounts to an aluminum case with "not as advertised" inside - I'd very much recommend pingbattery.com for your LiFePO4 needs, I'd very strongly recommend against anything other then LiFePO4 - the battery is so very much the most important component on an ebike
