might do a little preping if I find a good backpack

I have this campers backpack that is pretty awesome, was bought many years ago (from my childhood, Im 33 yrs old now). But its just too big. I need something I can wear while I ride a horse or motorcycle. This one the frame goes down near or past the buttocks :xeye: and I cant sit comfortably with it on my back.

Do they make a nice one of similar size at least, and can strap a sleeping bag on the top, and other things on outside of backpack easily?

Im not really a prepper kind of person,but I am considering doing some preping, especially since aliens are coming back Dec 2012 and no one knows their intentions. :

Cant find the pic of my backpack, but will look more