Thought I'd share my toner results. I ended up using my regular feria silver blonde to re dye the roots, then worked the remaining dye through the ends. I'd usually only do this for the last 5 mins but I left it on for 20 this time to lift the colour. I followed it with the superdrug 99p toner that I finally managed to get hold of. I got a much paler result than usual - hardly any yellow tones. This is how it turned out.
It's slightly greyish round the front from the toner but thats ok because I'm planning on dying silver over the top. Glad I decided against the bleach bath in the end because the feria colour is much gentler on my hair - I have no idea why. Standard bleach makes my hair really straw like but this stuff is magic.