I have about the same milage on my 330ci. And its a totally different car now that its been boosted. THe only downside I see in your application is that its a 2.8. Not that its a big deal but spedning 6500$ on a SC plus install and parts will run you 8 g -ish. Now 8 grand and your car might be a great downpayment on the new 335i.
"One thing we all adore. Something worth dying for..
Its been nothing but pain, stuck in this game. Searching for fortune and fame