Blender will be a good solution for pretty much everything 3D. Yes, you can import pretty much every 3D Model you can find that is in a blender or common format. Yes, you can do animations just fine.

Be aware though that

1) you will need to learn the basics of 3D Modelling and animation first before you can do anything useful in blender (lots of tutorials should get you up and running in no time),

2) Blender uses a very weird control scheme for the uninitiatet (lots of hotkeys, so keep a hotkey cheat sheet ready for your version of Blender... yes, they differ between versions!),

3) depending on how realistic the animation should be, there are additional steps needed before animation (rigging, setting bones and weightpainting your hand mesh so you can animate fingers independently with the mesh reacting to deformations), and the whole animation will get much more complicated.

thanks Gian-Reto - can I ask to anyone

a) Is there an obvious alternative to Blender that you might recommend for someone on a Mac that would be more intuitive? I'd be willing to pay say up to ~$200 if it speeds the rampup up. (I did come across Cheetah for Mac, http://www.cheetah3d.com/ , not sure if it's one of the more highly used tools however)

b) Is there a way/place/site to search for model's that would already have the rigging/bones etc set up? i.e. so you'd just import and use the timeline and set keypoints by only having to move the bones? No doubt the cost for such a model might be higher, but it would save quite a bit of time I'm assuming.

thanks Kryzon - I wouldn't have thought to put "FPS" in the search...

good point StarMire - however if I want to get a set of images (that form the animation) and I want the non-hands pieces to have alpha=0, then it would be easier using Blender right? i.e. if you record via camera I'm not sure how you'd do this?

Before you do anything on the computer you first have to decide what kind of visual that you're after.

Are you looking for realistic hands? How about cartoon hands? This will help you decide what tool to use.

You can use those FPS hands and animate\render them on Blender, this gives a certain result (example).

You can record your own hands with a camera and then manually cut out the background parts frame-by-frame using Photoshop. This gives another result (example).

You can import the footage into Anime Studio and rotoscope your hands. Then you can shade them in any way you want (example), but I recommend staying close to realism.

thanks Kryzon - I'm thinking it might be best in the long run to run with the Blender approach & I can reuse this in the future for other game art...