Racetech emulators - what fork oil?

Hi all,

Just got a pair of Racetech emulators for my curvy which I'm planning to fit this week.
Racetech's calculator recommended 74.5 springs and 20w fork oil for my weight / riding style (70kg without gear / commuting, with a bit of fun on the side).
I've decided to stick with the standard springs for now as they're not too far off (might try some 80's at a later date if I decide they're too soft).
Just wondered if I should still go for 20w oil with 70 springs? Doesn't 20w oil sound a little on the heavy side?

Any tips/advice on fitting the emulators would be helpful too!

Thanks all,

-Skov