Guidance needed for replacement Sony sound system for fiesta

Hi all,

New to this forum and hope someone can help. I have a 2011 fiesta titanium and my sound system has been playing up for the past few months. Majority of the time the control freezes so I can't adjust station volume etc and only rarely can use the control on the steering wheel. Other times the station displays but sound cuts out. A mechanic did a diagnosic check and said it was coming up with the ua100 bus circuit error. When I spoke to a guy in Ford service the other day they said it was an issue with the system and I would need to pay over 650pound to replace or try somewhere like Halford to get a replacement unit but wouldn't be able to use Bluetooth anymore. Bit gutted as I've never had a sound system go that quick and they just said it was unusual but out of warrantee. I'm trying to locate a replacement myself for ford to fit to save on cost but needed some guidance on where to find. Thanks all, pic of system attached. The ford guy at first insisted over the phone it was a German brand that would cost a lot and no point of paying for diagnostic check +70pound just to be told the same but when i pointed out it was sony he said that meant an even higher price...I need a replacement 😐