Waters is looking at three NASCAR Cup starts with leading team Roush Fenway Keselowski Racing.
The secret deal is done, awaiting confirmation in the wake of his one-year renewal with Tickford Racing.
Waters wants to join Shane van Gisbergen, making a full-time switch to NASCAR, and Kostecki as a street/road course race guest driver.
Kostecki has signed with Richard Childress Racing for selected NASCAR Cup races.
Waters connected with powerhouse team RFK during a pre-Bathurst 1000 trip to the States.
His Monster sponsorship ties facilitated introductions, with the energy drink giant keen to back his switch to NASCAR.
Supercars drivers are in demand following SVG's stunning NASCAR Cup debut win at the inaugural Chicago street race.
They're valuable because race wins get teams into the NASCAR Cup Playoffs, worth millions of dollars.
Waters has renewed with Tickford Racing for at least another year, leading a slimmed-down two-car team alongside Thomas Randle.
His renewal was signed nearly three months ago, with the official announcement delayed by complications with Tickford's contraction.
The new deal allows Waters to pursue racing opportunities overseas next year – specifically NASCAR – before he commits to Supercars in 2025.
While coy on his NASCAR aspirations, Waters confirms that he wants to race overseas at classic tracks, as well as reiterating his desire to compete regularly in the USA.
The latest Speedcafe Newcast also hears from Shane van Gisbergen about his big move to America.
SVG quietly relocated after the Adelaide 500 and is now setting up his new home – and his new life – in Charlotte, North Carolina.