If you're stuck on the idea of PBJ in tubes:

Skippy Squeez'it is 9 oz. of creamy peanut butter in a toothpaste tube.

If 9 oz. is too much, you can get Squeeze Stix - individual portions of peanut butter in tubes (like GoGurt).

Then there's Squeezers - peanut butter in 1/2-oz condiment packets.

While I was looking up those three items I ran across P.B. Slices which are individually-wrapped peanut butter slices - just like Kraft cheese! Not sure how well they'll hold up on the trail, but for me it was one of those "I never knew..." moments.

For the jelly you'll just have to use something like Coghlan's Squeeze Tubes. I couldn't find any jelly products in tubes. If you end up buying them from REI, use the site portal so the board gets some support.

I get my PB and jelly in the restaurant-style individual portions. My friend's wife distributes free lunches to low-income kids. I make a donation and she gives me a lunch box full of PB & J with single-serving packs of crackers. I can get the same thing from a restaurant supply store, but the last time I did the jelly turned into rubber before I could finish the box of 200 (can't spread rubber on bread or crackers). This way I get a fresh batch every other month and 10 kids get lunches for a week.