what accessory belts to use with underdriven pulley?

[Surge]

I've just finished installing a new timing belt and damaged my old crank pulley in the process.

So I bought a lightweight under drive pulley similar to this:
http://www.streettuned.com.au/Engine-Ac ... _1321.html

The problem is that now my accessory belts are too long for use with this pulley. I'm going to have to buy new belts but I dont know how long they should be.

Does anyone have a part number for suitible belts?

The only thing I can find online is this:
http://www.wrxtuners.com/forums/f52/und ... post209028
Gates K050330 (855mm) and Gates K040340 (880mm).

Cheers
Serg