Problem with futaba is yes most of their receivers are big and quite heavy compared to others. Other major problem is you talk about running multiple cars and receivers and at £70+ a go things will get expensive very soon.
Stick to a major brand like Spektrum, Ko Propo, Futaba, Sanwa, etc.
Spektrum are good value for money. Used to have a DX3S which had everything you need and good feel. You can pick up the orange specktrum copy receivers from hobbyking for £5-£7 as well which work fine.
Personally i use a Ko Propo Helios ex10 with specktrum module and receivers. Nice big transmitter for big hands and you can angle the wheel with the drop angle wheel attachment which means your wrist isn't at silly angles. Ko propo are expensive but if you buy a decent model you've got a transmitter for the next 10 years.