But that is not the caseless DIY shelf-servers they've displayed in various PR videos.
According to Wikipedia, the 2U models were indeed based on Dell PowerEdge servers, and the 1U models were apparently based on Super Micro servers.[^1]
They figured out that it was more efficient to have hardware techs spend 100% of their time provisioning new hardware, and just let their software detect the broken servers, power them down, and route the tasks to working servers.
Depending on what specifically you're after, there's a number of them on ebay: https://www.ebay.com/sch/i.html?_nkw=google+search+appliance
They want the spyware to run on your hardware. They don't need it on their hardware. If there is spyware on Goog's hardware, I'd be looking at it coming from certain three letter agencies or other nation states.