wow, that sucks what your toby did...thats exactly what im trying to avoid...lol
My porcupine puffer hasn't touched any of my corals yet, he will get a snail here and there, but there are some snails that have been alive for over a year in my 125g tank
I don't have any shrimp in that tank, I might try some and see how long they last
Another option are Green Spotted Puffers, you're more likely to see them listed as brackish or even freshwater fish but they do great in saltwater and as adults really should be in SW.
Like any other puffer they vary in personality and apatite from fish to fish but I've got 2 in my 90 gallon mixed reef and other than occasionally snagging a smaller snail or hermit they've been fine. Definitely wouldn't risk them with shrimp though.