I spent a good few hours last week checking around for a clip on to go with the NS1000s I have on the way, and never really seen much. There's the zalman mic that you see recommended everywhere, and it looks like it will do the job. I decided to take a chance on this
speedlink clip on, it says it has noise cancellation, and living in the highlands it's a struggle to get free postage, so it worked out cheaper aswell. I'll post back next week if it's any good, but my search for something better is on going