All:
Unless you want merely say 6" extensions... I would recommend just getting the cart - I'd be worried about tipping and stability.
For starters, it is stainless steel, tough stuff, and no rust.
No hassle - upon arrival you are set. If one considers let's say making something out of wood or steel, there's time and material involved and so forth, it will rust or rot and need painted every year.
The only thing that would make the cart better is if it had a drawer option and or a front shelf that mounted in an easy secure fashion... But at some point you have an over designed cart that would cost a heckuva lot more.
I'm fine with it as is and I have made a few mods so far... And if I want to add some other custom features I can do those over time... Such as adding utensil hooks and so on.
Attached again is the mod done to the tables to secure the in place to prevent a bump and fall