If you're hoping for both, consider the 40 2.8 and the 85 1.8. The 85 1.8 would give you a nice portait lens (when you find models) and a very good low light telephoto lens for crop bodies...
+1 well done FTb-n...Heck yes...why didn't I think of that too!
The 85 f/1.8 sounds like a perfect fit for you. It's a terrific lens, especially for the price. Fast, bright & sharp. There you go. Problem solved.