I need a high speed network connection between 2 database servers on
IBM Netfinity servers.
What are my options and what hardware do I need?

I was looking to gigabit ethernet first, as I figured it would be the
cheapest.
But a sysadmin I know said he wasn't sure but he thought about $4,000
for two cards and a switch.

Is it really that much for gigabit hardware?
Is gigabit the cheapest alternative?
What kind of switch is required?
What's the difference between a switch and a hub?
What's the actual transfer rate you can achieve?
1,000,000,000 bits per sec/ 8bits = 125,000,000 bytes per sec
125,000,000 bytes  per sec / reality =~ 20MB/sec I'm guessing.

If someone is familiar with this, could you send me some part numbers I
can look-up?

Thanks.

Paul