Good job with the install and detailing it. I was considering the Blackberry bluetooth gateway but if you can't do phone calls over it, I'd rather not use it. Maybe a Parrot or the Alpine unit.
The only thing with your install is you have to buy an iPod touch to make it work, so the cost of the install is pretty high, unless you already own one - which *I* do but others may not.
For the landscape mode coverflow issue, I suggest checking out a program called Flicktunes which uses gestures and allows access to music in landscape mode.