Would this work? I've ordered a similar Optima Yellow Top for my 2007 and had my shop install it. I changed the input on Amazon to a 2008 like yours, and this is what the site says fits:

https://www.amazon.com/Optima-Batteries-8171-767-DS46B24R-YellowTop/dp/B006VFEJJQ/ref=sr\_1\_1?crid=O43KMYTHY4P4&keywords=optima+yellow+top+battery&qid=1683425441&sprefix=yellow+top+battery%2Caps%2C185&sr=1-1&vehicle=2008-76-1026------------2&vehicleName=2008+Toyota+Prius