keg build kits , or prebuilt ?

[planohog]

I want to change to electric 1/2 keg . I will need to incorporate a 220V element , drain, and end up with 2" triclamp fitting .
I see these kits online. search convert-A-Keg, the only kit on the market that makes it possible to turn an old beer keg into a boiler
Is this a good start ? How will I convert from 4 " inch colum coupler to a 2in coupler.
I would be open to exploring a ready to go assembly. I do not need a condenser or riser or motor controller for 220. I do need a heating element.
Any help would be great, I have searched , I find many amazon solutions that seem wrong. Thanks in advance.