There's a 4th option - make it yourself.  That's not "oh pfft! Go make it yourself!".  That is instead saying, you can learn and delight in creating new models if you have the temperament, creativity and drive to do so.  In a way, Poser and DS and the like are shells or players that require you to stick something in them.  There are certainly things to explore that are beyond the program if you are feeling limited.

You could play with material nodes and create/discover all kinds new things.  Or play with different render engines via 3rd parties.

You could could up with little python tools and snippets that make Poser more interesting and they're certainly some creative fun in doing that.

Another thing to muse over:  If I render the models I have made and rigged, I do think it's an artistic endeavor and certainly has some additional depth to it.  Though I also have no problem with what folks might consider compositional art.  Load things, compose, pose, etc. click Render and for some it's still thrilling and fun.  And clearly people all render to different degrees, some are very talented and have grasp of placement, evoking emotion (isn't that art?), telling a story with a single image, setting up lighting and using it effectively and so on.

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