Hi,
I have direct experience of two-way satellite broadband. In my opinion it's only good as an absolute last resort.
Latency for gameplay is key as someone else has already said, the ping times I saw on that (BT supplied) kit was horrendous, > 1,300 ms.
The transfer rate downstream is good, but the typical usage allowances are poor value.
If you don't get an automatic tracking dish then it will become the bain of your existance trying to align it, these are significantly more touchy than a Sky dish.
Try a 3G dongle first, it might not work in a few places but it's nothing compaired to two-way sat comms.