2006 Octavia Mk2 1Z Audience HU Update

Well all of my older issues ( engine misfiring, low performance and delayed DSG upshifting) got fine, it was because of a damaged intercooler-turbo pipe. Since then the car has been running really well - great performance and returning good economy too (6.2l/100km). 

I was planning to update the installed head unit Audience. I was wondering what all can fit in since my car has steering controls and parking system. I was thinking to upgrade to Bolero or columbus but will my existing steering wheel controls work and what about the bluetooth controls? Another thing is parking because the newer ones use OPS so how much will OPS cost? 

Also my DSG gear shift knob is bit worn out, is it possible to take the leather out and get it replaced?