5-w30 on my cap, 6.5qts written under my hood. That includes the filter because I always change it. Also the miles at each oil change which averages 5,000 miles, same interval I've used on every car I've ever owned. I use 5W-20 since my Hondas do too.Interesting - the oil filler cap on my '11 V6 has the oil weight, but not the quantity. Seems that the quantity would be variable, depending for example on whether the oil filter has been changed.
You will need exactly the same thing that you needed for the 5w30 oil changes, except the bottle will say "Synthetic" on it. Mobil-1 is good stuff, generally around $22-$24 at Walmart or Amazon prime for a 5qt jug.
Stay with whatever weight is listed on your oil filler cap... likely 5w30, but possibly 5w20 for a 4.3
If you have moderate to high mileage, I would stick with 5w30. There is only a slight economy benefit to 5w20, at the expense of less protection in high temperatures.