Similar to above I went through a few combinations, my main priority was portability alongside a good “vape”.
I ended up now using a Kanger Mini Protank 3 clearomiser (the tank that holds the liquid along with the replaceable wick / heating coil unit, and houses the mouthpiece most importantly!) with an eGO fitment battery (eGO refers to the connection type for the battery). Links to both items (just as examples!) are as follows but you can find them in many shops with a quick search.
Kanger Mini Protank 3
eGO Battery
In terms of liquid it’s pretty much find what you like, I do like the “Ruthless” eJuices imported form the US but there are a tonne of UK boutique producers, your best bet is to find a shop with a reasonable range and you can try.
Do fire up any more questions if you have them, the getting started phase of vaping can be a bit confusing, we’ve all been there!