That Ksport coil over looks kind of short, AUD$1,600 is way too expensive for what you need. You are not sure if they will even fit. Most coil overs are made in China with bad struts, likely crapped out after 20K miles.
The best and most reliable strut brand is KYB made in Japan. Buy the KYB AGX adjustable struts with life-time warranty and have a mechanic assemble them into the old springs. Those spring will never break and you are sure the car will be at factory height with adjustable struts damping from soft to hard. KYB AGX struts are about $100 a piece. KYB EXCEL G struts are not adjustable and are cheaper about $80.
KYB 734021 AGX Front Right Twin-Tube Adjustable Strut for 00-05 Toyota Celica
https://www.ebay.com/itm/294962089320KYB Front & Rear Shock Strut Assembly Set of 4 for 2000-2005 Toyota Celica 1.8L
https://www.ebay.com/itm/152028410125