The latest approved version of the list is 6.8
http://www.taccmd.tacticalwargames.net/ ... 23&t=29531 which has a number of points changes.
Looking at your list I would say personally I prefer a few more formations at 4000 pts. However if you really want to use a Manta that might be difficult. I would still try to get up to 15 activations if you can and if you really want the Manta it might be a good idea to include a spaceship to allow for the flexibility of planetfalling. If you use the planetfalling ability you could also potentially remove the need for Orcas.
I would also personally prefer smaller more flexible support armour formations.
So maybe something like
Mech Fire Warrior Cadre + Skyray, Pts = 325
Mech Fire Warrior Cadre + Skyray, Pts = 325
Fire Warrior Cadre, Pts = 225
Broadside Group, Pts = 300
Crisis Battlesuit Cadre + Shas'o + Drones, Pts = 350
Crisis Battlesuit Cadre, Pts = 250
Recon Skimmer Group, Pts = 175
Recon Skimmer Group, Pts = 175
Recon Skimmer Group, Pts = 175
Skysweep Support Group, Pts = 250
Armour Support Group, Pts = 225
Armour Support Group, Pts = 225
Manta, Pts = 650
Barracuda Squadron, Pts = 150
Protector, Pts = 200
But really the best thing to do is try some lists out that you like and see what works for you. Just be aware the Tau in epic can be a fairly tricky list to get the hang of.