well here's a quick simple guide...
wireless routers support 3 exsisting ways of using wireless networking.
1:Wireless 'B' - very old now and not very good range also not very good transfer speeds - do not get one
2:Wireless 'G' - pretty good, i'd say its the most commenly used and will get network throughout your house, unless you live in a big big house
also transfer speeds are usually 108mbp/s or i think they do a 300mbp/s
3:Wireless 'N' - the netwest, i can;t tell you much about these, but i can assure you they will be worth the money if you plan on having a big network.
personally i think the wireless G range will be fine and for the price range im sure you can pick one up from somehwere, have you tried newegg?