Question : How to combine networks from two ISP's into one

I'm setting up an office in Thailand, and the networks here are compared to Europe very slow and unreliable. So i have two ISP's  (TT&T and CAT. ) One is ADSL and the other GHDSL (whatever that is....). Both give me an modem that output an ethernet (lan) cable.

So my problem is, how do i combine this two nets into one? I guess i need either two or three network cards in one server and then a switch after the server. Can XP pro handle this?

Answer : How to combine networks from two ISP's into one

Easiest, most reliable way would be with a dual WAN router.