Hi, i'm looking for a mod and an rta, i do not like the idea of constantly dripping but like the idea of cheaper coils, i vape regularly throughout the day and was using a alien 220w mod with a baby beast tank but i have maybe dropped my mod one time too many haha, so i'm looking to buy a new mod and an rta, however i am not interested in mechanical mods or mods that can not be charged via micro usb, any suggestions will be very helpful, thanks in advance, i also live in the u.k. so would prefer only uk websites to be buying from, again thanks.
If that isn't a wide open question that has one million answers.

It might help to narrow it down quite a bit.
First, for charging via the USB, I highly suggest a single battery mod. most mods out there don't balance charge easily if they take 18650's. So, for reliable charging via USB, I'd recommend either a built in battery, or a single battery mod.
You say you vape between 50-100 watts. For that, I do recommend a built in battery or a 2+ battery mod with an external charger.
Now, something comes to mind when I read your post, if you're going from a pre-built coil to a RTA, chances are you might find a preferred vape with totally different settings as your pre-built coils. I friends running baby beasts running a .2 ohm coil at 70 watts, but I pull out my .7 ohm coil in an RTA running at 30 watts, and they say my RTA produces more flavor, and just as much vapor as theirs. I think it's a mixture of wicking and coil making, but it does show that an RTA can produce a better vape with the same stats.
As far as what RTA I'd recommend, well, I will just say what I use, and that's a goblin mini or a Griffin. Neither of those atomizers are for everyone, but it's what I like. I prefer bottom fill to avoid any vacuum issues. both the griffin and goblin are fairly easy to wick leak free. Another tank I like that has both pre-built coils and an RTA, is the TFV4... the newer versions are probably better, but it's what I have. It is a big tank.