Flyrant is obviously the best choice. Proxy some Devourers or do some customization on warrior arms if you must, but they're the wrong size. Carnifex Devourer arms are the right size for the sockets. Two sets of them. Wings and Haywire template which is never represented on the model. Since there's no points limit, go crazy. So much of the Nid stuff isn't represented on the model. Fighter Ace is a big one to grab from the White Dwarf or supplement, which ever you have on hand. Norn Crown, toxic blood, really, go nuts.
Warriors may as well get sword and whip and Deathspitters. Add every upgrade available to them, and there's many. Nids are the most mutable, but it costs an arm and a leg, so people don't do it. You don't have that issue it seems, so make them regret no point restrictions. The tournament shouldn't be a big challenge that way.
If you can, add more Warriors. If it's JUST started box contents then oh well, but if you can bump that brood up, do it. And make them look nice because unless you magnetize, you'll never use these models in the configuration you'll have them in again. It's hugely wasteful but Warriors are not in a good place otherwise.