Been looking over the Tau codex, and really looking for a way to help them deal with characters, and by extent, psychic powers...
My answer is a Wayfinder - an HQ choice representing a pathfinder leader.
A Wayfinder was once a bonded pathfinder. During a single battle, all but they were slain. Unable to integrate into a new squad, they travel as escorts for the water caste and scouts for the main army. Those that survive dedicate themselves to guiding their fellow pathfinders, eventually becoming their mentor.
Wayfinder - 85 pts including all wargear
M WS BS S T W A LD SV
6 5+ 3+ 3 3 4 2 8 4+
Longshot Pulse Rifle: as per codex
Markerlight: as per codex
Photon Grenades: as per codex
Vanguard: as per codex
Recon Suite: as per codex
For the Greater Good: per Codex
Fire on my Target: When selecting a target to fire at, that target counts as having one additional marker light than they do for all shooting attacks directed at them. Furthermore, if this Wayfarer successfully hits a character, then a single unit of pathfinders within 6" may also fire on the same target, regardless of normal character rules.
Dismemberment Disbursement field: A wayfarer and any units of pathfinders within 6" are -1 to hit provided they are in cover and did not move in their previous movement phase
So, first things first - this character is expensive. I am not sure by how much, but I figured better to go a tad high and then scales it down.
The only three real differences are the two special rules and the fact s/he has a 3+ bs. It has always bothered me that the Tau army seems to jump from mediocre ballistic skill to amazing, with little progression between...
The first rule, Fire on my target, is designed to allows more and varied snipers to the Tau forces. The 2nd is to help those same new-fangled-sniper-wannabes to live just a tad longer...