So I am working on getting some equipment to put together a CCNA lab. Currently I have:
2 x 2950C switches
1 x 2514 router with 2 serial and 2 AUI (With ethernet transceivers)
1 x 2621 with 2 fast ethernet ports
I am looking to get one more router. Any ideas on what I should get and what type of ports it should have?
I was looking at maybe a 3640...but most of the ones on ebay come with no modules. So if I go this route, what modules should I get? I found a Cisco NM-2E2W 2 Port Ethernet Module for $55.00 on ebay. So I could get this and put it into the 3640. Do I need more serial ports to handle the frame relay scenarios?
Any recommendations? Do I need T1 ports if I don't have any T1s in my house?

I have looked at the FAQs, and don't really see what type of ports I should be looking for on the routers.