Connecting two USB *clients* together (SiK radio problem)
Arduino doesn't sound like the platform of choice here, but you're clearly on the right path:

You're looking for a platform that makes it easy to configure your controller's USB interface as host.

An easy solution would be a fully blown application processor board – an Odroid, a raspberry Pi, or a lot of other Linux boards would be as easy as it gets to set this up.

On the lower-power, less comfortable scale of things would be microcontroller with native USB support, together with a somewhat sensible OS for these that makes USB handling easy. Your application sounds a lot like ARM's mbed platform's target use case, so I'd start there – they have a whole galery of supported devices, starting from USD 5 eval boards to fully blown ARM computers.

Personally, that would be something you can hack together with nothing but a QFN breakout board and a Cypress PSoC4 running ChibiOS, but honestly, that's pretty far from beginner-friendly.