Since you're in Houston....years ago KHOU-TV had a time card system that used these T5700 things. When they decommissioned that system the IT manager was told to junk all the hardware. He just couldn't bring himself to do it, so he passed it to me. I once had about eight of them. No down to just two remaining. The PCI expansions kits were once available for about $30 each. Now they're a bit hard to find.
The expansion kit yields room for the installation of an internal hard drive. I once had one with a 250GB 2.5" HD running FreeNAS with the SlimNAS (Logitech SqueezeCenter) music server plug-in.
You can buy HP thin client cheap via their SMB outlet. I've seen them for around $150 on average. Depends what specs you need. I see that they've gone up in recent times.