openlayers 2 - Retrieving tiles in EPSG:4326 format. Is there a service for that like CloudMade?

Is there a service that can provide custom tiles in the EPSG:4326 projection? I've looked at Cloudmade and it would be the ideal solution but their tiles are using Spherical Mercator.

Basically the end result I'm looking for is to create a square grid overlay on a map. Like this : http://openlayers.org/dev/examples/graticule.html

So retrieving the maps via WMS would be a good choice but I need the map to be custom styled like you would be able to do in cloudmade. But maps like cloudmade and google maps seem to distort the world and so a square grid won't be possible on their tiles if i wanted to create the grid by equal increments of latitude and longitude.