A goliath is also a giant.
Nope. It's a monstrous humanoid.
You might be thinking of Goliath in my Mythic Sagas game, where I use Goliath as half giants, and give them the giant type.
Granted, you've got some limitations to for this "troll" character, as far as HD/levels, but getting actual regeneration along with fast healing is usually
really nice. It effectively gives you Regeneration of a value equal to your regen + your fast healing, and then at the point all your subdual damage is healed, the fast healing goes on to heal your lethal fire/acid, etc, damage. A shadow creature Troll is nice for this, as is a Half-Troll War Troll (war trolls are normally monstrous humanoids...) Of course, I'm speaking from the perspective of a DM...