I've never tried ducting, though i hear it helps.
There are more economical choices out there...as long as you get a decent HS/Fan, some good thermal paste (applied properly), and have good air flow in the case, ...you will do fine.
Once you decide on a HS/Fan combo, you should then read some reviews on it, just to make sure their are no issues that may hamper your efforts at cooling. If you go to www.ncix.com
, you can see customer reviews on most products (this is a Canadian store so prices will seem high-CND dollars).