I have made good experiences with http://www.logilink.eu/showproduct/UA0095.htm connection my RPi to 3 wireless devices. It ships with 3.5A power supply, for example via amzn.
How much do the USB miner draw power? In my mind, it is around 500mA .. so the power-supply won't be enough 
Personally, I'm a fan of Exsys, which provides devices for industrial purposes.
This one: EXSYS EX-1177HMV have the correct alignment of the USB Ports and can be powered by any external PSU. .. Range 7V - 24Volt ; so you can reuse anything you currently have (PC-PSU, whatever)...
I'm using for rechargeing USB Devices and powering USB Routers this one EXSYS EX-1177 which has enough Power to give every Port 500mA (see Datasheet)
(I know, it is a bit expensive..)
regards Gaim
edit: lol, someone else was faster..