"what do i need to purchase to surf web on both comps at same time" You don't mention a router in your post. Do you have one? I can here the FE *sigh* but your question "surf web on both comps at same time" would be answered by just feeding a crossover cable between the two machines and running a P2P network.
Thank you, spikeychris. On rereading the problem I realised that I had assumed that cfcpaul1888 had a router. You are quite correct that if he has a USB ADSL modem, all he needs is one crossover cable between the two computers.