It's quite easy for someone to say that your equipment is not the best out there. Especially when they have a store full of other options.
The EVOD is an older design for sure, but it's still a pretty solid performer and many people use them and are quite happy with them. They are simple to fill, easy to use, have decent airflow, flavor and vapor (when they wick correctly!) Capacity is only 1.5ml on a standard EVOD though, so many people like the larger clearos so they can go the whole day on one fill.
But all that said, there are clearomizers on the market that are considered 'better'.
Better in this case usually means they have adjustable airflow so you can change it depending on the thickness of the liquid you are vaping to improve wicking and the draw through the device.
Some also have dual coils, which will provide more vapor and flavor. The newest ones right now have a different coil design that positions the coil vertically in the air chamber and has the wicking material wrapped around it. This again provides better flavor and vapor when compared to your EVOD.
And of course some clearos are up to 10mls in capacity. So it's very difficult to give you advice regarding the 'best' clearo out there as for every person that say X is best, you'll see another post where X is giving them all sorts of fits to get working correctly.
Currently, I see more people seem to be happy with the Aspire that stiiinger mentioned above, there is also the aspire nautilus mini (that will probably sit better on a twist type battery) as well as the Kanger Aerotank.
As for batteries, genuine vision spinners and joytech twists are probably the way to go. There are numerous poor quality batteries out there and I would only recommend these two brands. I think there is also a winder from smok that I have seen positive posts about. All three offer similar performance with similar pricing - around $18-28 depending on vendor and mAh.