If you were to use this:
http://www.sallyexpress.com/viewProduct.aspx?pid=021926
You would get the ash but not add any more colour.
You need to make sure the developer you're using is 10% Vol.
Any higher and it will lighten the hair and bring out the under tones.

The best colours are Topchic. They're very 'true'.
Sally's stock them:
http://www.sallyexpress.com/search.aspx?q=topchic
Topchic does the 'A' & 'NA'.
They do some 'violet' colours which would tone down golds.
Have a look at http://www.sleekhair.com/7602.html
This is a pale violet that would neutralise gold.
Color : Blonding-Cream Ash
item # 7602-Blonding-Cream-Ash
Or:
Color : P-MIX - Pearl Mix
item # 7602-P-MIX

This is pure blue and quite dark:
Color : A-MIX - Ash Mix
item # 7602-A-MIX
Or:
Color : Blue Ash
item # 7602-Blue-Ash

My recommendation is Goldwell Topchic P-MIX.
Its a pale blue 'pearl' colour.