I find that 2d6 initiative dice, along with a base initative of at least 9 (ensuring that 2 passes always happens) is enough for a secondary combatant like the face or decker (assuming it isn't a combat decker).
For a Face character or other mundane, I will often just give them the Booster, for it's flat 1d6 for only 10k nuyen, since I usually don't have to have them min-maxed to fit as much 'ware into their body as possible.
The use of combat drugs can also be important. If combat is likely, a dose of Cram can go a long way to making you more capable. It lasts for a while too, so you don't need to use it that much.
That's what I did for my Face character but then got a slew of suggestions form the missions group that I needed to have at least two levels of Synaptic Boosting and/or combat drugs.
Considering over 90,000 of her resources went to 'ware that assisted her her in her primary skill (Tailored Pheromones 3) and she had at least 60,000 devoted to fake IDs/licenses (important for her role) as well as other implants like Muscle Toner to give her enough Agility so she actually could be somewhat effective with a gun, armour mods like SmartSkin Nanoware so if things went south she wouldn't go down after the first shot, boosting for Perception so she wasn't caught off guard, and high fashion armour clothing to impress the Johnson that she meant biz,, that was not a possibility even with A level priorities. It also meant less for skills or attributes just to have enough resources to cover the all the 'ware.
I really miss the million nuyen [insert archetype here]. Crikey even 600,000 would be nice as most bioware (which is more Essence, thus Social Limit friendly) was not reduced in price since 3rd ED.