Replacing the Superb mk1 MFD with.........

I'm looking to update the oem with another double din aftermarket unit, but my questions are as follows!

The CD changer I'd like to keep, is there a particular manufacturer whom can supply an adapter?

The GPS antenna, is it a standard connector on the back of the oem?

Do I need to purchase adash adapter kit, do they look oem if I do (some look awful)!

Any recommendations on HU? I'd like to combine my BT and sat nav into the unit but I need it to be a decent nav system as I use it daily.

Thanks all stay safe.