E34 535i exhaust replacement options?

[silversleeper]

I know it's not necessarily an E30, but my dad's 535i has a rusty old muffler that is too loud for his liking. What is a good, affordable replacement that won't rust out in any time soon?

Okay, between the three main choices that I could find, which would you go with and why?

Eberspaecher?
Ansa?
or Bosal?