Dura Ace 7410 with flat bars - which levers?

[ekallus]

Hi

I'm building a flat bar bike and want to use my 7410 8 speed groupset.

Can anyone tell me which Shimano Sti combined brake/gear levers for flat bars will give the correct shifting?

The closest I can find is the Str 221 but I'm worried about accurate shifting as I believe the 7410 used a different amount of cable pull to any other Shimano mech.

Thanks
Ernst