You're right that fiber makes no sense for 10G workstations; the optical transcievers alone will set you back $1000-2000 per port depending on vendor. I assume you have plenty of confidence your workstation hardware will be able to pump out the data quickly enough, and your storage will be able to consume it quickly enough to make 10G worthwhile.
If so, you could look at any 10GBASE-T offering, assuming all of your cable runs are under 100m. All other copper-based 10G standards are short-reach (in-rack) solutions.
Cisco doesn't have a fixed-configuration 10GBASE-T offering to my knowledge (and it would probably be priced insanely if they did). I would look at any vendors who offer 24-port 10GBASE-T. However, many 10G switches are 48 ports or more, which is a lot more than you need (I assume cost is a factor). So the selection is somewhat limited. Arista, SMC, and Extreme all have 1U 24-port 10GBASE-T switches to my knowledge. All are likely based on the same merchant switching silicon and will have similar performance.
There's no such thing as "cheap" 10G switches yet, even 10GBASE-T. Expect to pay $500+ per switch port, and $500+ per NIC as well (Intel). Still, 10GBASE-T is far cheaper than fiber, which is more than double the price because you need to buy optics for both ends of each fiber run. Most 10G devices are still aimed at the datacenter, so they will have a lot of layer-3 and enterprise-oriented management/security features you won't use. But you will still pay for those features.
Update: I just ran across this Dell PowerConnect 8024 switch that offers 24 ports of 10GBASE-T starting at US$5000, or about $200 per port. That's a far better price-per-port than what I've seen from other vendors.