Sadly, the "look like a different type of metahuman in metahuman form" option for shifters is really, really bad. Like terrible. You pay 20 bp for low-light vision. Please don't do this, just be a regular Shapeshifter.
First, you should understand what being a Shapeshifter does for you - you pay a lot of points for Regeneration and hopefully better stats (although some of the animal types have really bad stats). You also get Dual Natured which has some advantages, but comes with the major drawback of being unable to hide from astral enemies. This means you have to be ready to kung fu fight on the astral with ranged combat, ie, you had best know Stunbolt.
There are basically two ways to go as a Shapeshifter shaman. One is to focus primarily on casting - basically, you wind up being a typical magician who has less good casting (because you spent a lot of points on Shapeshifter) but has the very powerful Regeneration ability. The other is to focus on buffing yourself and doing physical combat. Do note that fighting in animal form is always bad because of the lack of equipment; you should use animal form to try to look like a normal animal or in very rare cases where you need something specific (ie, Eagle shapeshifters might turn into an eagle and fly away sometimes), but doing things like being a Tiger shifter and planning to hang out in Tiger form and fight like that won't work out well.
Of the shifter types:
Foxes are pretty bad
Wolves are awful
Eagles are good at the casty type; they bring Charisma and Willpower bonuses, and flight in animal form is nifty.
Tiger/Lion are good at the fighty type; they bring huge stat bonuses (but have 1/5 willpower)
Seal are similar to Tiger/Lion, probably very slightly worse but it's debatable.
Leapord/Jaguar are similar to Tiger/Lion and strictly worse, but not dramatically so.
Bear are good at either fighty type or casty type; they have lousy agility but enormous Body, and slightly subpar mental stats.
Anaconda shifters are not bad, but not a good idea as a Shaman because of their different mental stat mods compared to other shifters (they'd be good at either fighty or casty type, but with a Intuition or Logic tradition).