Williams is nicknamed Quadzilla because of his enormous thighs.
His best 100m time of 10.10s is slightly faster than Isles', and he has a background in rugby at his Brisbane high school and is said to have dabbled in league.
American speedster Perry Baker, rated the best sevens player in the world, is another inspiration.
"I've been watching a few highlights with Carlin Isles and Perry Baker - it's about trying to do what they can do," Williams told the Sydney Morning Herald.
"I'll try and burn them [opposition defenders] on the outside.
"I'm sure the coaches and boys are going to help me with anything I can't do perfectly.
"I've always loved the sport and when the opportunity came across to play sevens for Australia and even possibly the Olympics next year it was a bit hard to say no to that.
"They came to me after nationals and offered me to come along and pass the ball around and see how things went. I then went down to Sydney and did some skills work with [coach] Tim Walsh. They were pretty happy with what I could do and it went from there."
Aussie athletics is disappointed to lose Williams, but sevens coach Walsh said: ""We've identified that a key area we need to improve on is adding more speed to our squad - players with sprinting backgrounds have made excellent converts to the game."
Williams represented Australia recently at the IAAF world relays meeting in Japan.
