What is the best external microphone for iPad Air? Primarily for interviews...

I produce DSLR videos and record audio separately, then both are synced on my iMac. I used to use my iPod Touch (4th Gen) as a pocket mic with my Seinheiser lavalier, but it died in a tragic wash/dry cycle and I now use my new iPad Air.

Unfortunately, my Seinheiser mic is designed with a screw-on mic input, which rattles and pops my audio from time to time. I am familiar with the very inexpensive iRig line (and their accompanying mobile apps), but you get what you pay for and I am looking to invest in something higher quality.

The Air is pretty new and I dont expect there to be a lot of options, but given the limitations of the headphone port, I am hoping for the best.

Much appreciated!

- Caron