I cannot imagine that a hi-tech version of a flaming sword would be harder to make or find than a magic version. I assume you're already adding cyberarms to your character, so that's essence loss to start with. I skipped 4th edition, so I don't know if that's the trick or if there is a new (to me) four armed metatype.
I imagine that you can make a flaming sword with today's technology, although I can't figure out why you'd want to. The wounds would cauterize as you swung, staunching the bleeding immediately. It would be shocking and painful as hell, but much less fatal. Conventional metals would lose their temper, so you'd need to make the sword out of some other material, like ceramic or perhaps monofilament. On the other hand, a glowing hot blade would cut through some armors like butter.
I would stat it out like a monosword with better armor penetration and a battery pack from the laser rifles/pistols.
Then, take a cue from Rurouni Kenshin, and give it a sawtooth jagged blade that traps the blood, fat and meat from your enemies, which combusts when the sword is hot. That would be properly terrifying.
Now wrap that all up in a package at a comparable price to a monowhip.
