NU Sun is generally Hyper Offense with 2 setters and four abusers. The two single best setters are probably Liepard as the Prankster setter and Explosion Regirock. Typically you would lead Regirock to set up your rocks and weather, then explode to get a free switch-in into your sweepers. Liepard comes in later in the game to set the sun again and act as general utility, especially against sweepers you might not be able to handle otherwise. There's little other choices, really; only Volbeat comes to mind, but it's not as good as Liepard.
Premier sun sweepers include Shiftry, Sawsbuck, Victreebel and Exeggutor, while the most common Fire-type abuser would be Pyroar due to being acceptably fast, but Magmortar can work just as well.
While this is the most common and arguably most useful build, you can go a more "balanced" route by cutting back on straight-up abusers and bringing Pokemon with defensive synergy or that would otherwise benefit the team.
Premier sun sweepers include Shiftry, Sawsbuck, Victreebel and Exeggutor, while the most common Fire-type abuser would be Pyroar due to being acceptably fast, but Magmortar can work just as well.
While this is the most common and arguably most useful build, you can go a more "balanced" route by cutting back on straight-up abusers and bringing Pokemon with defensive synergy or that would otherwise benefit the team.