Hey all,
I recently purchased a Jamis Parker II for my intro into DH. I want to shave a few pounds off the bike (I am a roadie and used to ultra light bikes) but dont want to affect the integrity for DH. I am thinking switching to CF for the seatpost, handlebars, etc but was also looking for more experienced guidance in DH. I am an agressive rider and know I will push the bike. Forgive my ignorance to DH, but want a major change from the road. Thanks for all your help!

It's a noble goal but why are you interested in shaving weight yet when you are just starting out? I would suggest getting the feel for riding DH and determining, after you've ridden a while, where you want to upgrade.

BTW, picky things like handlebars and seatpost are the last things you should look at (and think twice about CF). Your efforts are much better spent at the unsprung-weight end of the bike (wheels, tires, tubes, etc.) Just be aware too, that weight-saving efforts with components still robust enough for DH carry a hefty price tag too. You could end up sinking more into your Parker than it's worth quickly.

+1 dminor

...and keep an eye on your chainstays.

no offense meant, but if you lose 5 lbs it would equal about $500 in parts upgrades.

(I have no idea of your physical condition, just throwing out a good cheap way to lighten up the burden)