As far as your suspension - For the front I would recomend you move up to .33 KG springs (thats best for people 140-170#, stock springs work best for people under 140#). For the rear you should prolly get 4.6 KG spring (works best for riders under 150#, the stock springs work best for riders between 180-210#).
The idea of drilling the air box is to get more air in without allowing any additional dirt in (keep that in mind).
www.justkdx.com - Has some good info on hop-ups!
www.eric-gorr.com - Has some really good info about jetting & everything else.....Maybe you should buy his book?
I think with the additonal power you have added to the bike you would really benifit from the new springs and an mxtech revalve! It is expensive, but totaly worth it from what I hear. I will get it done as soon as I have the money.
You need to learn to jet, like srhill said, the only way for a mechanic (even the best ones) to get it perfect is for them to watch and study you actually ride. (they have to study all different aspects of your riding) I know I don't have the money for that.
Good luck,
Tom
BTW - How do you like the pro circut pipe? How was the fit? Is it for low-end or top-end? The silencer?