those picket st wheels and tyres look awesome. i'd go with them on the firestorm. as long as they're 12mm hex theyre grand.
i think a couple of the ftx shells fit, the bugsta being one and the carnage ... i think would fit. Just have a look through and check dimensions. from what i've seen and heard, most 1/10 truggy shells can be made to fit, with some shenanigans.
apparently the ese white ball ends upgrade for the blitz are great hop ups. I plan on getting some myself as my stock ends keep popping off recently.