Recording commentary indoors

Hi,

I need to record a video for web using a DV Camcorder. The camcorder has a single input for the microphone. All recording takes place indoors in a small ecoey room. The recording will be one person sitting in a chair providing commentary. I'd like the voice to be clear without any background fuzz. Which type of microphone would you recommend? I would prefer a tie clip mic for visual effect but am not sure which one to buy?

Many thanks,

James