I'm having a hard time finding the 3D Models fro autodesk maya...

[Ladia Nexen]

Hi I am looking for the 3D Avi models for Designing and RIgging mesh... I'm also looking for the ones for photoshop as well. 

[Rolig Loon]

Almost everything you're looking for is at http://wiki.secondlife.com/wiki/Clothing_Tutorials

[Codewarrior Congrejo]

The default avatar files for Maya,  can be either taken from Wiz Daxters plugin: bg.blogspot.dk/p/slav-maya.html
(but be aware that only the purchiased version offers custom avatars and other features)

Or from here: 

here: https://jira.secondlife.com/secure/attachment/59951/Default+Male+%26+Female+Rigged+Avatars.zip 
(it should include several file formats / inclusive Maya readable ones) 
Or:  http://msstyle.host56.com/secondlife/_Default_Meshes/

Another one that works good is : http://blog.machinimatrix.org/wp-content/uploads/2011/12/SL-avatar-rigg.dae

For Photoshop you can use any OBJ based model, as i.e. the ones from here : http://wiki.secondlife.com/wiki/Clothing_Tutorials