With only eight days, I agree with the previous poster to stay in Lisbon, especially if you want a relaxing trip. You can easily do several day trips from there, including Evora, Setúbal or Cascais to those already mentioned.
Regarding restaurants, there are too many to narrow it down. I use the Google restaurant reviews when I travel and am rarely disappointed. At least once, try one of the small ‘typical’ Portuguese restaurants. They will have a Prato do Dia, or plate of the day for €10-12. Have Pastel da Nata at Manteigaria, maybe throw in seafood at Ramiro, and be certain to have Rabalo or Dorada (typical fish). You can also find Michellin star restaurants, if you want to splurge.