Having already won the inaugural Quokka (1200m) earlier this year, Overpass completed the Ascot feature sprint double in Saturday's $1.5 million event and won his first Group 1 in the process.
The five-year-old won the Quokka for the RAM Racing Syndicate slot earlier this year and is set to defend his title for the same slot holder next April.
Darby said he hoped Darby Racing may have more than one representative in next year's Quokka, indicating he was keen to secure a start with recent feature race winner Insurrection.
"He's a horse that Michael Freedman, his trainer, nominated for the Winterbottom," Darby told TABradio.
"He probably thought it was just a little bit too soon, but he's mentioned a number of times The Quokka could be a really nice race for him.
"He came out of winter form and we're wondering if he will continue on that trajectory upwards.
"We're going to nominate him for the Razor Sharp (Handicap) on Saturday and that will be his first attempt at 1200 metres.
"That will give us a good pointer going forward whether he's strictly 1000 and 1100 or 1200 will be his go as well."
As well as targeting the riches of The Quokka, Darby said he's also looking forward to attending the Perth Magic Millions Sale in February and possibly racing horses in Perth.
"We had lunch with David (Houston) from Magic Millions on Friday and he floated the idea we may look to syndicate a couple over here," he said.
"It looks like it's all systems go to potentially come over here in February and looking at buying one or two and extend the arm of Darby Racing in WA."