Wheelbuilding / Wheel Building / Wheel build help

Found these 26" ryde css rims (like mavic ceramic, sort of) but only in 28h drilling. ebay.co.uk/itm/391563713732

Will be used on an old rim brake mtb that probably won't see much action -

You sure you want ceramic rims if you're not going to use the bike much?

Likely to have poor braking until they're worn in - consensus in other places is that can be 1000km (ish, and with road use, so no doubt less off road). Special brake pads too ...