Carnivorous plants

I have a 10 gallon tank I want to use to make a bog style terrarium for my utricularia plants (sandersonii blue form, reniformis, sandersonii ‘angry bunnies’)

I have a pitcher plant and a drosera spatulata that I’d like to add in. But I’m not sure how to go about it. Would sphagnum moss by itself be a suitable substrate?

Should I forget about adding the drosera and pitcher because of possible root rot?

Would I have to worry about gnats since whatever substrate I use is going to wet?