I have a smoant cylon on order, and I'm excited for it. I also have a revenger kit (Vapresso) that I like a fair amount, although I'm not really a high wattage vaper. Well designed mod, drinks battery life a bit if you leave it on.
One of my favorite two battery mods that is less expensive would be the Eleaf Invoke. It provides a good amount of power, is small and lightweight, if you want TC it seems to function decently, although not as precisely as a DNA mod, which if you think you will use temperature control a lot, it might be worth investing in one, although they are pricier. I will say, I like my Eleaf invoke as it's one of the lightest two battery mods I have, and the form factor is great in the hand, without sacrificing build quality. I've dropped it a few times, nothing bad happened.
As far as building, my advice is to start with an RTA or RBA that looks like it will suit your preferences and is single coil. Velocity style decks, as mentioned before, are somewhat easier to build on.
You will need to figure out what wick and wire you want to use. A coilmaster kit can be helpful (it was to me starting out) and contains everything you will need to start building. Steam-engine.org is useful to start trying to calculate builds and resistance.
Take it slow, continue asking questions along the way, watch some reviews/tutorials for what you select to learn how to build and wick them, those are usually helpful. You can also get prebuilt coils if you wish, you will still need to install them. Wicking can be tricky at first, too, but overall everything gets easier, as you start completing the tasks to get you ready for building.. A good place to start might be in the rebuildable atomizer forums, there is a lot of good and helpful information there.
Welcome to ECF and best of luck,
Anna