Cheers matey, that second one looks good. I don't mind screwing it to the dash, or using some massively strong double sided tape. I'm probably going to end up scrapping the car or trading it when I'm done with it, so minor blemishes on the dash don't bother me.
One of those Aliexpress RCD330s is certainly an option. The main reason for the mount is to monitor the engine with an app, so looking down at the radio screen in boost might not be best for safety