As mentioned elsewhere, I'm opposed to seeing sniper gun drones align with PF's. They are apples and oranges.
Just because they both have 4 man squads, both have 3 rail rifles with target locks - doesn't mean they are the same type of unit or even belong in the same type of formation.
The PF's are forward scouts, calling in CF, and taking shots at targets of opportunity, while marking targets for the army and remaining very mobile in the DF's.
The SGDT are operated by a FIRE WARRIOR drone contrller, not an elite trained PATHFINDER. The SGDT do not ride in DF in core design and are not nearly as mobile as a result. They do not mark targets for the rest of the army, they only mark targets for themselves. They are not scouts. They do not call in CF for the army in any way shape or form. They also benefit from the stealth shield generator to virually conceal them from all but the closest enemy units.
Apples and oranges when comparing SGDT to PF's. We would NOT be doing the core design justice to mix these two very different concepts IMHO.
Physical models - I imagine a FW drone controller with tripod and 3 drones per stand. From a conversion stand point, a FW with crisis body (no extremities) would get close to setting up the controller. The drones with Rail rifles are easier. Regular drones with longer central mount gun (pole) or whatever would get you pretty close. Converting a stand would probably be pretty easy actually.
In game terms, its pretty much a given that the SGDT would have Rail rifles with Target lock as a weapon profile. I see the network markerlight as a bonus to their 'to hit' value in their weapon stats - as that's all we've really done in the past. The SGDT definitely deserve Sniper ability in E:A.
I think we should revise the stealth field generator to no shots at them unless within 30cm range - period. (I think the same should be for the stealth teams too - I also think I'm alone on this point, but anything else is a gross abstraction of the intended effect by the designers).
I also think the Rail rifle should have an AT value of 6+. Like the Stealth Field generator suggestion - I'm sure I stand alone on these two fronts. However, I wanted to express my opinion nonetheless.
As an UPGRADE to a formation, the SGDT would be a no brainer as 3 units of 4 models (1 controller, 3 drones) if we looked at Tau Empires for guidance of a unit size. I think the 3 units makes sense as an upgrade size in E:A as that's what a single force org choice is in 40K. The SGDT unit type would align closest with the FW Cadre as an UPGRADE since the drone controller is a FIRE WARRIOR. The problem is we get into using them in a fashion that they weren't even intended for. They are meant to be the ghost. The invisible formation out there that the enemy must get close to in order to deal with. (heh - just like the stealths) so my preference is to NOT see these as an upgrade, but as a stand alone formation. So moving on...
The SGDT clearly operate as indepenedents though - thus the stealth field generator to conceal them. That's why I prefer to see these guys implimented as a stand alone formation vs. an upgrade. If we wanted to, they could easily double in size for a stand alone formation of 6-units at the E:A scale. This is where the 'not being targetted unless within 30cm would come into play. Since the SGDT weapons are only 30cm themselves in E:A - can't really see this as being much of a problem frankly. Yes they are harder to kill because you have to be close - but that's the whole point.
With an AP and AT shot, the formation would be flexible and representative of the S6 weaponry.
Disrupt I could go either way on with this formation.
To me, these guys deliver SOO much more value to the E:A Tau in a stand alone formation role when compared to the promise of the Stingwing Vespids.
Just my thoughts though.
Cheers,