I have read several times that some rokkor users says that 45mm f/2 is pretty interesting lens for it's lenght/apperuture and bokeh, also I've seen some very pleasant samples via flickr etc.
Besides 50mm f/3.5, good option might be 58mm 1.4 lens, if focusing isn't close enough to replace the macro, then it's better than 45mm f/2 for DOF shots and portraits. I'm using mine and loving mine very much.
The 58/1.4MC is very sweet.This old "long" normal length is perfect as a short portrait lens--great bokeh and speed, too. It's the main reason I keep looking for a cheap X700 just to use it again.
Yes the 58 f1.4 is a really nice lens, I actually sold it a few months back because i picked up the 50mm f1.7 rokkor-x which is slightly slower but much sharper.