Definitely this! I'm having trouble finding one of these on the web for a decent price + reliable source. Adagio already has some yixing pots, it seems like this and a kyusu are the only things that are missing!
I would suggest Yunnan Sourcing. If you are in the US they have a site here as well. They have a couple of REALLY cheap gaiwans on both sites and I have one myself that I can tell you works perfectly. I would be nice to see our wonderful host to TeaChat offer such a thing though. That's my two cents.