There are lots and lots of choices and many reasonably priced. I would suggest you consider getting a mod with removable batteries. This way you avoid any downtime because you can just carry extra batteries.
I have not used this one -- but I had considered it
https://www.directvapor.com/premium-mods/eleaf-
istick-pico-25-vape-starter-kit.html
It has the box mod plus the tank and you just have to change out your batteries and the coils.
You can get it cheaper - you have to look around.
I use a very basic setup - Kanger Toptank mini. It is a bit older - has the box and a top fill tank. it takes coils plus it is expandable. It does temperature and wattage mode and comes with an RBA piece so I can build my own coils.
You can also get ones with the battery built in - the thing is --if the battery dies the whole box is no good whereas with one that takes batteries you just get new batteries as needed.
When I moved up from an ego to a mod I noticed a big difference and enjoyed vaping more.
How much are you looking to spend? If you throw out a ballpark figure -nothing it too high or low --I am sure you can get some great recommendations.