Emon Pi - all I need to do mains panel monitoring? Where to buy?

I have an old cobbled together monitoring solution from a cc128 and want to get a better setup. The tx4 thing seems to also need a ‘base’. Is the emon Pi meant to be the all-in-one approach that senses and also can send to the web via tcp/ip not just to a 433mhz node?

If so, where do I buy one?

Or, I have a couple pi3’s downstairs, can I just buy the bits I need and flash an image onto one of those?

Thanks!

You can buy all you need from the shop

If you look around n here, there are several guides to DIY