Hi - I'm surprised he didn't refuse after awhile. Many chams get tired of the same old thing - you're lucky! but it is good to vary the diet. Silkworms, roaches, butterworms, superworms (mmmmm- Luna loves supers!), you can collect the ocasional wild insect but make sure no pesticides, herbicides, etc. have been sprayed. A relatively safe one is moths at your lights (please no luna or polyphemus moths!). Some adult moths don't feed at all and those that do feed on nectar (pesticide issue is only real concern). it's also good to have something flying around for him to catch for tongue exercise 
The link I gave you for Bugs' Nutrition has the chart - check it out - the whole artciel is good. Check out their other issues -it's a great online cham e-zine!
As for gutloading - feed your crickets quality foods: fresh fruit and veggies (no spinach) and a good dry gutload. Since crix will eat just about anything they are easy. Just keep the food fresh so no mold/bacteria grows. Just remember - what you feed your crix is what you are feeding your cham. What have you been doing so far? Do you use calcium and vitamin supplements?
lele
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0.1 veiled - Luna
0.2 house geckos - Gaia & Tia (both MIA 
0.2 felines - Kyndra and Líta
1.0 African Clawed Frog (for summer)
0.5 Mad. Hissers (for summer - all girls, no little ones, whew!)