SMC are indeed 10m, and are here:
SMC Contour maps - Installation GuideYou can get custom contour sets using GroundTruth:
GroundTruth - OpenStreetMap Wiki - they use the same DEM, the Shuttle one. You can specify your intervals IIRC.
(my to-do list has had "get new contours for uk using this" on it for ages...)
I don't know a tracks-only layer. To make one yourself you'd edit the mkgmap style-file to ignore highway=most things, by just deleting those lines, and ignore all POI and areas with empty files.
Personally, I'd keep the munkymap handy and swap when you wanted the stregth of either it or navigator, but I would say that, wouldn't I?