Use time capsule as a router, or just as backup device?

[I'm a Mac]

Here is my setup: an iMac (aluminum), an HP laptop, and a sony laptop- the only one with "n" is the iMac. Right now, we're using a D-Link router that is kind of broken and needs to be replaced. However, we have a few third-party wireless (non-n) repeaters throughout the house, and I wasn't sure if time capsule was compatible with them. So do you think I should buy another router and keep the time capsule connected ethernet or "n" to the imac, or should I use it as a router?

Also, if I have a time capsule, can I use it with airport express and third-party repeaters?

 

[windowpain]

You can definitely use the express to extend your network. If you wire it to the base station you can have one transmit a "n" signal and the other transmit a "b/g" for your other stuff.

Not sure about the other routers though..