Lots of beer kits are made by a company called Muntons. Including the Woodford ones.
https://www.muntons.com/
I don't think they put anything magic or secret in - just the same malts and hops that Woodford use themselves. Like I said, the water is important and the yeasts that come with kits should be thrown away and replaced with a decent yeast from your local home brew shop.
I find this is really good:
https://www.thehomebrewforum.co.uk/
I prefer to bottle my beer rather than use barrels, but it's very much a personal thing.