Hello,
I don't recommend 3Com and I also don't recommend Dell (For Switchs). Most of Dell products are Unmanaged which means that you don't get an actual interface to manage it via the web.
Go with Cisco and pickup one on eBay. You can pickup a Cisco 24 Port Switch for around $300 on eBay.
I've decided i'll just get the cisco switch and setup a squid reverse caching proxy - this offers best performance/price for us and allows us to load balance the way we want to as well as cache to offload during peak hours.