Tie Rod - can't get the right one!

Hi
I wonder if anyone else has this problem or knows a solution. I need to replace the tie rod (rack to trackrod end. Mine has a 12mm thread into the rack, and all the motor factors can only supply one with a bigger diameter thread. It's a standard power assisted rack. The car was originally on a R plate (pre facelift)

The NISSAN dealer doesn't show it as a separate part, only the complete rack is available.

Before anyone asks, the old one is a bit bent following a coming together with a kerb on a rally in Caerwent, in which I snapped the wishbone (which pulled the drive shaft out of the box wrecking the inner CV boot)and bent the back axle and panhard rod. Oh I also wrecked a tyre when the wishbone snapped and the wheel came back into the arch locking it. We stopped in a cloud of tyre smoke.

andy had a similar problem http://www.micra.org.uk/threads/what-did-you-do-to-your-micra-today.43944/page-204#post-613403

Frank -thanks. Odd thing is it is the reverse problem. He had the 14mm and could only find 12mm. I want 12mm and can only get 14mm. I'm even more confused.