Hi Oliver, it's amazing!

re: renderer, see here for some ideas:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5166.6

Also more discussion here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3136.1

Like Burr mentions in that first thread, it looks like Bryce is still free for the moment, so you may want to grab that:
http://www.daz3d.com/products/bryce/bryce-what-is-bryce

Some of these renderers do not like to handle complex n-gons so when you export out from MoI, use OBJ format and set the option for "Export: Quads & Triangles" rather than "Export: N-gons".

- Michael