Regarding Pixel 8 or Pro: It all depends on what you are looking for: You can compare the specs here and see what is important to you.
Whether you want the bundle or not also depends on how much data you are willing to give to Google: For the bundle, as far as I know, you have to buy the watch directly from the Google Store, or - if you buy the product elsewhere, later register the IMEI 1 of your phone on a special promo page and enter your address there, where the Pixel Watch or Buds will be sent.
Google can then link IMEI, bank account/PayPal, credit card with a name and mailing address. Or you can buy the phone anonymously and pay cash - but unfortunately you won't get the Buds or the watch.