For kindergarten, I would say just get a small backpack- one with Tinkerbell or something is about the right size. For one, your child really will not need a heavy-duty backpack yet. Believe me, there will be plenty of time for that, coming up!
My son had a Spiderman backpack for pre-school and kindergarten and a Spiderman insulated lunchbox. The lunchbox did not make it through the year, but we ended up passing the backpack on to someone else.
Now he is going into 5th grade. he has been using a heavy-duty backpack since 1st grade, but has requested one with wheels for this coming year, because he has a lot more homework and heavier books to carry now. I am planning to invest on a good quality one from Lands End, which hopefully will see him through high school!
We have been using the same insulated cloth lunchbox with a shoulder carrying strap since about 2nd grade. It came from Target and has worked just fine all this time.
As the kids get older, boys especially don't seem to need as much 'decorated' stuff- my son puts his own stickers, etc. on his backpacks and lunchbox now. Get your kids the silly, little kid stuff now, while its age-appropriate. They will need heavy-duty gear before you know it!