Can somebody please provide me advice on how/where I can purchase a DJI RC with a colour display compatible with the Mavic 2 Pro? Failing that if there are available suitable RC models manufactured by a 3rd party?         My gratitude would be perpetual for any advice offered. Thanks.    Paul R.

Look for 2nd hand SC (Smart Controller) you will Not be disappointed!

Make sure you get the DJI RM 500 the other controllers with a screen are not compatible.  

Hi there. Thank you for reaching out. The DJI Mavic 2 Pro can only be used with the DJI Smart Controller (DJI RC or DJI RC Pro not supported). This specific controller is no longer available as brand-new or refurbished on our official store website. You may click the link below to possibly purchase the said controller. Hope this helps.

https://www.dji.com/uk/where-to-buy/retail-stores