Thank you Gents!
John, I exclusively use the Deltang receivers, now supplied by Andy at Micron RC. The equipment has been totally reliable, can be re-configured, and is teeny (this receiver is 10mm square and has the electronic speed controller biult in). All this for a touch under £30.
You can use any transmitter capable of 2.4ghz DSM2 protocol (I used to pick up the basic two stick E-flight ones for twenty quid or less).
You can use any modern servos (I tend to get the smallest I can find on Ebay)
Deltang also to transmitters and receivers suited and configured to locos, which also work well.
Needless to say, I have no connection other than as a needy customer......
Best
Giles