My solution to the Vertical Pi issue is a bit complicated but not that bad... and i think gives the best results for little work:
I run 240p output into a CRT tv via composite...
1) Attract Mode as your front end.
2) On the AM forum there is a custom theme builder. I used that to make a SIDEWAYS theme that is a full screen snap video with wheel art logo, and nothing else. When your monitor is rotated, the sideways theme is now upright. Which way you need to turn it depends on preference. Set up attract mode as you would if it were normal, assigning controls for next game etc.
3) The game itself i rotate within Retroarch, and not in the config using the "display_rotate". I am not certain, but several have mentioned that this is the least burdensome way to rotate with the Pi in order to preserve performance and focus on actual emulation.
The existing themes on Fried's(cant belive i thought it was fred... must be fried myself. im a primus fan too) page may be your ticket as well... im just about to see what hes got now.