Introduction
Nb. This guide assumes a certain familiarity with concepts such as base stats and common abbreviations for skill names.
Symbiants are the Shadowlands version of implants but unlike Rubi Ka implants you don't need to add clusters they come prebuilt. Also unlike RK implants rather than adding to just 3 skills they add to many. The symbiant head for instance adds to all nano skills (bm,mm,pm,mc,ts,si,fa,treat) and many more.
Here's a comparison of the nano skills from a typical ql120 bm/mm RK implant setup and a ql 120ish full symbiant set.
Rubi Ka cluster based implants
mm 63 bm 91 pm 26 mc 0 ts 63 si 0 (Letah's weaponless doc layout + pm)
Shadowlands symbiants
mm 123 bm 123 pm 121 mc 120 ts 120 si 123
See here for the full 120(ish) set
As you can see you can have your cake and eat it. This is also by no means the end of it - the set will also buff just about everything else you could need including base abilitites Treatment,First Aid, 600 to most ACs, Max health, Max nano, NCU, 150 defence modifier damage shielding heal delta and nano delta ... and thats only the ql120 set. Not only this it will buff them higher than even the most balanced RK set could come close to.
The only significant caveat to this is that apart from a small amount of MA and Bow there are no weapon buffs. There are also no evade bonuses other than nano resist. I suspect the route to happiness involves a careful mix of symbiants and RK implants.
Symbiants drop exclusively from pocket bosses - more on that later.
Availability
Unlike nearly every other profession there is only one symbiant set available to docs Support.
The jewel in the crown (as it were) of all the symbiants is the head, here is what the Support head buffs,
Intelligence,Psychic,Sense
MaxNanoEnergy,NanoPool
NanoC.Init ,NanoResist,Dimach
BiologicalMetamorphosis, MaterialMetamorphosis, PsychologicalModfication, MaterialCreation, SpaceTime, SensoryImprovement
Treatment,FirstAid
PoisonAc
ComputerLiteracy,QuantumFT,ElectricalEngineering
TrapDisarm ,Perception
The Support set avaialable in qls 1-300 in steps of about 10. Note, not all parts exist at all qls. For instance the Support ql140 set does not include a head but the 120 does.
Requirements
Unfortunately symbiants are not very easy on your base stats + treatment. Every single base stat is required somewhere - though you can focus on some more than others.
All symbiants have high treatment reqs for their level - great for docs. Here are the requirements for each type,
Agility + Sense + Intelligence
brain
ear
l wrist
leg (thigh)
Agility + Sense + Strength
eye (ocular)
r arm
waist
r hand
Agility + Sense + Stamina
chest
feet
Agility + Sense + Psychic
l arm
r wrist
l hand
As you can see Agility/Sense are required regardless, so are probably a good starting point for things like armor choices at low levels.
Unfortunately they're not as buffable as Str/Stam. The most important places to implant for a doc are probably going to be head,chest followed by eye, r arm - though these two will hit weapon slots. So as a third skill Intelligence clearly, Str/Stam can be buffed. This does mean IP hungry docs are going to need to look at Agi/Sen compatible RK layouts when trying to mix symbs and implants.