3G modem support for SnapGear products

We want to purchase some 3G dongles which we can plug directly into our clients Snap Gear routers to use in the event of a SHDSL outage but I can’t get a definitive answer from anyone, including McAfee as to which device to ask when going to a retail store.

I’ve found this KB which tells me supported devices https://kc.mcafee.com/corporate/index?page=content&id=KB65670&pmv=print

But it’s not very helpful though when you enter a store and say to the retailer that you need a 3G modem that is compatible with a Snap Gear unit.

Does anyone know of an exact product whether it be from Telstra, Optus, 3, Vodafone that I can ask for which will be compatible with Snap Gears.