I've used the 98SE SP a while back and it worked perfectly alright.
For ME I did all the tweaking manually as no unofficial SP's for ME exist and until recently I didn't own an English version of ME. I tried the ME SP in a virtual PC and it seemed to work fine.
This English ME SP will install on a Dutch ME but it will turn your Dutch ME into a Dutch/English ME freakenstein! 😜
Edit:You can pick what to install and installing only things like tweakui and applying the tweaks shouldn't break the Dutch language thingy on a Dutch ME.
But do tweak ME if you plan to use it, ME does have problems when fresh out of the box but tweaking it should fix virtually all of the specific ME problems.
There is also 98SE2ME but, that's for English Windows only. Atm I still prefer a tweaked ME over a tweaked 98SE though, but that's more a matter of taste really 😉