Here's a pretty non-exhaustive list of New Zealand players who may handle the step up in my opinion. Hope this gives a bit of insight to those who don't follow the local leagues.
Sorted by position, with the more dominant players listed in bold, and bolters in italics. Biased towards younger players with room for development.
Goalkeepers:
Conor Tracey (Auckland City)
Scott Basalaj (Wellington Olympic)
Cameron Brown (Auckland City)
Damian Hirst (Birkenhead)
Sebastián Ciganda (Waiheke United, contingent on gaining citizenship)
Pieter-Taco Bierema (Selwyn United)
Defenders:
Adam Mitchell (Auckland City)
Taylor Schrijvers (Miramar Rangers/Melbourne Knights)
Sam Brotherton (Auckland City)
Kelvin Kalua (Eastern Suburbs)
Noah Billingsley (Christchurch United)
Justin Gulley (Wellington Olympic)
Nathan Lobo (Auckland City)
Ben Mata (Wellington Olympic)
Andrew Cromb (Birkenhead)
Midfielders (certainly being the hardest to pick for):
Cameron Howieson (Auckland City)
Te Atawhai Hudson-Wihongi (Auckland United)
Michael den Heijer (Auckland United)
Mario Ilich (Auckland City)
Wan Gatkek (Miramar Rangers)
Dane Schnell (Birkenhead)
Forwards:
Ryan de Vries (Auckland City)
Hamish Watson (Miramar Rangers)
Jack-Henry Sinclair (Wellington Olympic)
Dylan Manickum (Auckland City)
Jesse Randall (Wellington Olympic)
Gianni Bouzoukis (Wellington Olympic)
Joe Lee (Auckland City)
To top it off, here are a few of the teenage guns who have really impressed me this season, and may be worthy additions:
Mirko Brinkmann (Tauranga City)
Joe Knowles (Eastern Suburbs)
Oscar Mason (Napier City Rovers)
Owen Barnett (Miramar Rangers)
Adama Coulibaly (Western Springs)
Ralph Rutherford (Eastern Suburbs)
Oli Fay (Auckland United)
Albie Francis-Alles, Fraser Brown, Bruno Penney, Norman Garbett, et al. (Western Suburbs/Ole Academy)
Codey Phoenix (Birkenhead; Welsh U17 international but NZ citizen)
Keegan Kelly (East Coast Bays)
And for fun, the best Pacific players right now:
Raphael Lea'i (Henderson Eels, Solomon Islands)
Brian Kaltak (Auckland City, Vanuatu)
Sairusi Nalaubu (Lautoka, Fiji)
Teaonui Tehau (AS Venus, Tahiti)