Hey,
There is a difference between a modem and router. Modem takes the @@@ and sends it to your computer directly, Router takes @@@ and sends it to whatever computer on the network requested it. Routers are best if you wanna share things like files, printers and the lot. Routers are also great if you want to be able to use the internet at the same time and play games together on the internet at the same time. You know, all that good stuff....
Your modem's age should not affect how the router gets the internet. I mean mine is old (two years), and it works great still.
I have had bad luck with some of the wireless equipment I have bought over the years, but the D-link DGL-4300 is no exception, which is the router I am suggesting to you. It says its a gaming router. But even if your not a gamer, its a router will not disappoint. It gives me great speed, never restarts itself, and has range better than wireless N. I haven't compared its range to all the N routers out there, but it certainly impressed me compared to the old N I used to have. But I'm sure there are some out there with better range. But do NOT go with N yet, its still not official, its still in Draft mode. Which means it not true N.
This gaming router also feature great security (it can give you enterprise grade security, if you so desired). The router itself looks great on your desktop too, not a plain blue or white box.
The only complaint I have, is that the LED lights are blinding. It lights up my room at night, lol.
Also, the price may seem a little high for it, but it better to spend it all now, rather than spend some later, fixing your mistakes..
If you have any questions, ask. There's no such thing as a dumb question, especially in computers, lol.
Borgslayer