Congrats on the new lens!
180mm seems to be a bit of an orphan focal length (too close to 150, which is a common first lens, and too close to 210, which is more popular), so there are some really excellent lenses to be had at good prices. I have a Caltar II-N, which is the same as a Rodenstock Sironar-N or Apo-Sironar-N (my impression is that the "Apo" designation is just marketing, and does not reflect a real change in design, so find the one that's at the best price), and it's outstanding. Here are a couple of sample shots from the gallery--
(there was a url link here which no longer exists)
(there was a url link here which no longer exists)