be aware - if these are usb devices that people have had problems with usb.
it would help to list your computer configuration.
if you have a tower pc with pci slots a better solution imho is
a mixer like a yamaha mg feeding a delta sound card in a pci slot for example.
pci sound cards are more proven solutions.
search under my name. lots of posts on usb and other subjects that might be of interest to you before you make a purchase.
my saying as a puter engr is usb is for mice.