Define "Best" lol. There's lots of different, equally valid ways. I think most people buy shells from someone like RKD and then mod them to however they like. Others scratch build by getting PVC pipe and cutting and shaping it. Still others have metal ones.
Be careful with your computer device that it doesn't look too earthy
If you go look in the Tech brigade there's some good discussion about techy gauntlets, including things like scomp links (The computer interface tool that r2's use)
You can find many examples of flame throwers and dart guns on most people's gaunts around here. Just gotta do the looking