Saeco Via Venenzia/ Starbucks Barista

[Phat_Boy!]

Just bought a Saeco Via Venenzia or otherwise SADLY known as a Starbucks Barista
I think the machine is ok, however i hate the pressurized portafilter. Crema is bubbly and comes put in one big hit when the pressure pin drops. I would like to get a non pressurized one. Anyone know which brands if any are interchangable or where i can get one in Melbourne?
Thanks