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.
"We've come a long long way together. Through the hard times and the good.
I have to celebrate you baby,.. I have to praise you like I should.."