Dash and wheel finish - what spec?

I'm looking at moving up from an S3 to an S4, but looking through classifieds has shown that there seem to be quite a few dash specs, and at least 3 steering wheel options. I'm after the silver/aluminium inserts (not a fan of wood), with a multi-function wheel, maybe flat bottomed. Is there a certain year that this combo was or wasn't available? Does getting manual/auto make a difference?

Any help narrowing the search will be much appreciated.

Also, how easy/cheap would it be to retrofit nav/tv?

Thanks again,
Martin

That could be handy, I like bargaining tools I like them even more when the compromise is easy to remedy. Piano black would be nice, I'll let you know once I find the right car.

RNSE-wise, can it just swap out for all of the other units, or do you have to replace the climate switches on some?

What's the difference between B6 and B7 interiors? Is it just newer looking? Would retro-fitting the bigger nav screen into a B6 be a simple swap too?