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@Izan said, best you can hope for it to realistically reach 180W with current battery technology. Manufacturers just set their mods output limit to whatever they think sounds good.
Yes, you can buy pre-made coils. They sell them about everywhere vape supplies are sold.
I'm sure they make an RBA for your tank, but typically it is better to buy a tank designed for those kind of coils. They usually function a bit better and (depending on what you want and where you buy it) can cost roughly the same or just a little more than an RBA for a drop in coil tank.
What reason do you have for wanting to go up that high in wattage? It is absolutely possible to achieve similar (or the same) performance at lower wattage and have better battery life and not stress the batteries out by pushing them to their limits.