Growing up playing a lot of tabletop RPG's like Dungeons and Dragons, one of my favorites was a version called "Shadowrun" that was set in the criminalistic future, a world based on crime, guns, corporations, fixers for jobs, vehicles, explosives, hackers, mercenaries, gangs, etc.
One feature you could do while playing your character was pay for a "street doc" to install whats called "Cyberware" into your body after buying it from a drugged out cyberdealer who assures you its not ripped illegally from someone else and its definitely not a lvl 1 but the lvl 2 upgrade you're looking for, and came at a cost to your humanity, or "Essence" in the game, and you could only use so much before you weren't even human anymore, so there was a reasonable and playable limit (maybe happineess or total health in Torn or something can be substituted).
It would be amazing to add characters like a street doc to install cyberware and a dealer in cyberware to add things like:
"wired reflexes" to improve speed (they have lvls)
"dermal plating" for defense (they have levels)
"muscle replacement" for Strength (they have lvls) Retractable hand spurs (like finger razors) for unarmed bonus damage
Air filters for poisons (gas or mace would be ineffective or lessened)
"Cybereyes" for either thermal, night, or magnification (bonus in TCT time like nighttime, maybe a bonus to hit or helps with defending stealth attacks)
"Skillwires" where you can plug in certain skills, getting a bonus to its attempt. (I know kung-fu)
"Smartgun Link" is an adapter built into your hand and eyes, yes that would "cost" two augmentations, that goes to specific guns with the receiving adapter, (think of judge dredds gun, only less explody if you can't afford the feature and it just can't be used) but it gives bonus to control and aim by placing a cross hair in your vision when you aim with the gun.
These are just a few ideas from my old gaming days, and I would love to see them discussed as a potential add on to the game, as I'm basing my character Ehdrahil off of Shadowruns "Decker" class, which is a futuristic hacker class with a wide range of skills, cyberware like data jacks, (Johnny mnemonic anyone?) and futuristic keyboards, computers, and cyber decks where you have computer in your head and can jack into another with a wire built into your head that you pull out.
Anywho, just thought I'd share an idea.