Hi Adrian,Welcome to the forum
Thier are 3 companys that sell kits to build an R/C tank, They are Tamiya recognised as the Rolls Royce in the hobby this is reflected in the price of their products although as long as you follow the instructions you will have a perfect rendition of the prototype,
Then Taigen although you do have very limited choice of self build it allows you free choice in the control board you choose to use because their major product line is RTR(Ready to Run)Which comes with their own Control Board,
Finally Britains (Wales) Own Model Tank company (In 1/16) HAYA They sell a number of kits within their range including a very nice Centurion,
The biggest difference between these 3 is price, Any of them can be built by anyone who has ever built a model of similar size with relative ease, everything apart from the electronics is included and fitting an aftermarket control board is really pretty much a doddle,
And now we come to the meat

Heng Long, Taigen/Torro, Haya all make Ready to Run r/c Tanks and armour of most vehicles from 1939 through 2020 they come in different classes such as standard and premium which is reflected in fittings and price,
You can buy a brand new Heng Long Tiger 1 RTR out of the box except you provide the battery's for the transmitter whch comes with it (The Tank Battery is included) for under £200 or a kit for a Tiger 1 from Tamiya for £800/£1,000.
Taigen range from £300 to £600 and Haya From £300 to £700, there is another company relatively new to us in this hobby "Tongde" They make a limited range of RTR such as the Pershing and the Bradley and The Centurion they are very good value at around £250 to £400.
Many of us started with Heng Longs Tiger1, the present iteration is a very nice package with a control board that a few years back you would have paid a lot of money for it really is good.
There are more upgrades and aftermarket products for the Tiger 1 than any other 1/16 R/C Tank on the market,
Many parts of these different tanks are interchangeable BUT many are not BEWARE, Ask us if you are in any doubt,
Finally we come to what some would say is the most important part Which dealer to use,Dave and Julie at
www.forgebeartanks.com are as straight as an arrow and very helpful AVIOD "Nitrotec" Like the plague,
I shall leave others to expand on this subject.