Don't search so far, it's closer than you think.
http://wiki.maemo.org/Community_SSU/FeaturesStable

And little advice about desktop, remove all icons, add it again, arrange in both modes.

Following maemo wiki, if you want "landscape orientation lock" install packet status-area-orientationlock-applet
And second advice: blacklist apps that won't work in portrait and using them will be difficult (camera-ui, image-viewer) if you don't know how, check last line of MY transitions.ini file that i gave you