Hello Jeff,

1)

I suppose IX= Internet Exchange point.

the device needs to support:

2 or more GE ports to connect to public Vlans of IXP.

One or more WAN links to connect to your network/ your customer network.

An interface for out of band management using an IPSec tunnel over the internet can be considered.

The device needs also to have cpu and memory to handle multiple eBGP sessions.

I would consider the following:

ASR1000

C7600

GSR

a Cisco 7200VXR NPE-G2 could be considered but it cannot handle traffic on two GE and on the WAN link(s)

depending on your needs

2)

gigaswitch for datacenter

classic solution at access layer

C4948-10GE

C6500 at distribution or even access layer.

Consider also pairs of C6500 developed as VSS pairs (require specific supervisors and WS 6708 or WS 6716 for the VSS bundle made of 10GE ports, WS6704 cannot be used for this_).

Last offer include the Nexus with its dumb satellites

avoid on C6500 all linecards that have an high oversubscription rate (the older ones connecting only to shared bus).

this is the key point: data transfers between servers can require long time so you cannot be confident in statistical multiplexing.

Hope to help

Giuseppe