That sounds like a great trip, and a good way to try touring.

If you don't pack heavily your bike should be fine. How much weight do you think you'll have?

When I tour with 4 panniers I have about 12 lbs total up front (6 lbs per pannier -- usually the tent and rainfly split between the panniers). And ~12lbs per pannier behind. So I have 35-40 lbs of gear, plus a 30lb bike, which is as much as I'd ever want to ride/carry. Think about how much weight you'd carry for backpacking and apply it to the bike. My rule of thumb there is no more than 1/3 of your weight. (30-35 lbs for me)

Also, keep in mind there will be a learning curve to riding a loaded bike. I commute with panniers a lot, but my loaded touring bike still takes a day or two to get used to. A bike with a load will handle differently, and respond slower to turning and stopping, especially if it's at all windy. Wheeeee!

Don't hesitate to keep your mileage modest! On one tour a few years ago we rode 70 miles on the first day and it was a big mistake! We were so fried at the end of the first day that we almost called off the rest of the tour. We took day 2 off and just walked around the town we were staying in. On day 3 we finally decided to keep going on our trip. We now keep day one short (40 miles) and we expect the first couple of days to be mentally or physically tough.

On our 12 day/500 mile tour last summer we had a few days that we only did ~25 miles. Some of those days included big mtn passes, and some of them were just easy days.