Is it possible to use Safari's Reading List on my Windows machine and have it synced with the one on my Mac/iOS devices?
According to Apple's support docs, Safari 5.1.1 for Windows will sync the Reading List via iCloud.
I believe you would need to have Safari up to date. Then, install the iCloud Windows control panel and configure it to sync Safari content.
Then, enable iCloud on all of your Mac/iOS devices, and you should be good to go.