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.
"So I'm drifting away like a feather in air, letting my soul take me away from the hurt and despair.
So I'm, keepin' it vertical forever elevator, riding the escalator to something that is greater.."
Official E46 OT Podcast