Mega Charizard Y, Torkoal, and Ninetales are your Drought-inducers. Apart from Charizard, the latter two can be equipped with a Heat Rock for a longer sun duration. Alternatively, you can run something fast/with Prankster and Sunny Day up that way.
Since Sun reduces Water damage by 50%, obviously strong Fire Pokemon get a bit of a boost here. But you don't want your team to be too Fire-heavy. A few 'mons with Chlorophyll, Solar Power, Leaf Guard, and/or Harvest can excel here. Since those are largely Grass-types, you can run something with Flash Fire to come in and take a now super-lethal Fire hit, or just something to cover their other weaknesses.
Morning Sun will also heal for a ridiculous amount, and there's also things with Weather Ball that now get a 100 BP Fire move, and that's before Sun boost. You'll also want something that can Rapid Spin or Defog reliably since Stealth Rock is going to murder you.
And if you want a different Mega, Mega Houndoom is stupid strong under Sun with Solar Power and its insane Special Attack. Mega Pidgeot doesn't get an obvious benefit, but a Sun-boosted Heat Wave from that thing would be pretty painful.
Obviously I can't just give you a straight team off the bat, we'll need some kind of baseline to work from. Weather teams in particular care more about synergy and covering for weaknesses than a standard team since it's really easy to lock yourself into just trying to benefit from the weather, which can easily make most of your team weak to one type without having any way to counter it. So I'd come up with an idea for a team you'd like, post it here, get feedback, test, test, and test, and then come back if you need to. Sun has plenty of good options to use and it mostly boils down to personal preference.
Luckily you've found the guy who practically lives for Sun teams ^_^
