I'd rather have radar invisibility on (advanced?) basilisks. They're the least used alien, and for good reason. Besides, radar invisibility would really fit them with their stealth fetishism.
Speaking about new items... how about an Energy Shield for humans ? Mutually exclusive with light armor or battlesuit. It would reduce first hit by 60 points of damage, but would take 6 (or something) seconds to reload after that. During that time you'd have NO protection whatsover, not even as much as regular light armor provides.
Not to make humans stronger or weaker, but to allow different playstyles.