Then you'll be limited to download .ma, .mb, .obj...on Turbo Squid you can do an Advanced Search which allows you to specify which file types you want (and then you can sort them by price).

I'm not sure which version of Maya you have, but I believe you can install the 3DS importer for the most recent editions using the Bonus Tools from the Area:

https://area.autodesk.com/downloads/