WTB Connect 30 kit or good seat for Dagger GTX

[Blacklodge]

Hi
Relatively new to this, but I bought a lovely GTX from a fantastic bloke near Matlock. Trouble is, the cockpit is very basic and though great for a few hours, can lead to flatbutt so I would like to buy a decent seat pad such as the one which comes with the GTX 8.1.
Can anyone tell me how to source one or possibly suggest an alternative?

Many thanks - this is a great forum and everyone has been really helpful