Make the slann the bsb. Optionally, take the standard of discipline. I would keep the TG. In a game this size, you will probably do well with them. Until the slann is forced into the front rank (I believe that will be when you are down to 1 model) or charged from the rear, the slann can still use the special rule that allows him to cast. Even if the slann is in combat, you will still be able to cast your Life spells that you need.
For the disciplines on the slann: Focused Rumination (1 power die added to each casting), Focus of mystery (all the spells), and becalming cogitation are the must have disciplines. At this points level, I would go for the first two.
Magic items on the slann: I always take cupped hands of the old ones (I roll a 1 on throne of vines a lot).
skink priest: In most of my games, I would take the lvl1 with a forbidden rod (d6 dice to the power pool, d3 wounds to the skink) along with an amulet that gives the 4+ vs the first wound. This will be hugely useful when you roll two 1s on the winds of magic. Also, in the last 4 months, I have only lost the skink priest 3-4 times to this. Well worth it.
For Core/Special troops: I always, ALWAYS take full command. You never know when you will need them. In the case of the saurus, I can see where the additional saurus would come in handy. But, if I am going to put a character (hero or lord) in the unit, a champion is a must.
Cold One Cavalry: They are not useless by any means. However, you have to take at least 10 to use them effectively. I will usually have at least a mounted scar-vet in there with them. If you do take them, make sure to take the banner as well (points allowing).
Get some:
Chameleons: These guys are probably the best scouting unit in the game. Why use skirmishers when you can use these guys and still hit and poison after moving, double tapping, and being at long range.
Salamanders: These are a must. In a list this size, I would take 1 unit of 2 or at least 1 unit of 1 with extra handler. Never accept a charge on these guys. Always flee (3d6 because they are war beasts). They can move (march) and shoot as well.
