Headphone Microphone with RJ11 (phone) jack

Hi,
I searched for 2 hours online and same offline but not got any headphone microphone with RJ11 (telephone) jack.

Basically I want a headset to be used with landline phone.
can we get something like this in bharat
http://www.ebay.com.au/itm/Telephone-Handsfree-...

but I dont want to buy a adaptor like this
http://shopping.rediff.com/product/callcenter-b...