Here are some feeders that I raise and do not find necessarily difficult. I've tried crickets and found them more of a hassle than quite a few of these:

As you said hornworms, silkworms, and in addition, roaches (green banana, dubia, madagascar), snails, various species of earthworms, wax worms, and superworms plus all of the intermediate and adult forms of the larval stages make good feeders too. PM me if you need further advice or want to start breeding any of these.