With stayer Options lining up later on the programme, the couple have picked three tough debut races from their new base.
"It could either be a very good day or we could get out butt kicked," said Peter Williams.
"But we have to start somewhere and it is not about us, it is about getting the right races for the horses."
Both Shuka and Planet Rock pleased Williams at the Te Aroha trials on Tuesday, Shuka winning his heat and Planet Rock finishing third in the 1000m open heat.
"She has settled into her new home very well and I couldn't be happier with how she is going into Monday," he said.
Planet Rock hasn't raced since winning the 1000 Guineas and clashes with new rivals in Dowager Queen and the unbeaten Xanadu in Monday's race, which will determine what path she takes for the rest of the season.
"Her owners would love her to win the Filly of the Year title now that she has a group one so that is the main long-term aim.
"But we will let her tell us with her run on Monday which way to go.
"If she looks like she will handle the extra distance we will follow the Filly of the Year path through the Royal Stakes and then the Oaks at Trentham.
"But if it looks like she is going to be better at 1600m then we could revert to the Karaka Mile next month."
Like Planet Rock, Shuka has also had a look at Ellerslie previously, having finished a luckless fifth, just a head from third in the Diamond Stakes in March.
"So I don't have to worry about the track with either of them and they are ready to go."
Williams says he and Dawn have been overwhelmed with the welcome they have received since bringing 16 horses north and he will be looking to bolster the stable at the Karaka sales next month.
"I have got owners who want to buy at the premier sale and the others so we will be trying our best there. But we have capacity for 25 horses so there is room for more.
"Really though, the move has gone very well and the biggest thing for us to get used to was the new track to work on.
"Until you have done that a fair few times it takes some getting to know but after the way the horses went at the trials yesterday [Tuesday] we are feeling pretty good about that part, too."
One rival Shuka won't have to worry about on Monday is Duckworth Lewis, with the in-form 3-year-old instead taking on the older horses in the $200,000 Zabeel Classic. He sneaked into the field as the last of the 14 acceptors and will carry just 52kg with Matamata jockey Michael Coleman in the saddle.
Another feature of the meeting will be the appearance of star Australian jockey Nash Rawiller, who is riding Doctor Fremantle in the Zabeel Classic.
TOUGH DEBUT
- Former Canterbury trainers Peter and Dawn Williams launch their new northern stable at Ellerslie on Monday.
- They have three-year-old stars Shuka and Planet Rock in two of the group races on
Boxing Day.
- Both trialled well at Te Aroha on Tuesday.
- Top Australian jockey Nash Rawiller will ride at the premier meeting
