What Whetstone to use on Wusthof Classic Ikon knife?

Hi, I just purchased a Wusthof Classic Ikon knife set, and would like some suggestions on what whetstone to buy for sharpening it. (mostly the 8" Chef's Knife).

I work in a kitchen, and use a whetstone there, so I am not a total rookie. But the stone I have at work is so worn that I can't even tell the Grit# on it.
I was thinking a double sided stone around 400 & 1000 JIS.
But there are so many different brands of whetstones out there.. Does it matter that much? As long as they have the same grit# ??

I would just be using the stone once or 2wice a year (depending on usage and how well it holds the edge). I don't want too course of a grit that will eat away too much at the knife.

Thanks.

The grit combo you mentioned would be good for Euro steel. Just buy a cheapser stone from a reputable brand and you are good to good. For example a naniwa super stone. The Kings are said to work quicker but wear out faster. Maybe worth considering if you only use it once or twice a year.

I think you could benefit from a finer stone as well. I regularly finish Wustoffs with 2 or 4k stones, though seldom higher.

Thanks, maybe i will get a 400/1000 combo stone as well as a 2000 stone to finish off with.