You can always order from 3 and see if it works from his house, no problem walking back into a shop and throwing it back at them, few customers of mine have done that if they have no signal at their homes down the country.
Generally all the mobile 'midband' stuff is useless for gaming, fine for email and static site browsing though.
Outside of that the only other option would be satellite from a provider like digiweb, and that's going to be more of the same, (bad latency, no good for gaming) but at least you are sure it would work with solid throughput.