Well, you can't make clothing models in illustrator to use in Poser. IF your skill is good enough, though, you can draw a picture of clothing to fit over the rendered picture of your Poser figure. IT takes a fair amount of skill to gt the lighting, textures, and compositing right, but it can be done. 'Simply' render your naked poser figure, and save the rendered image.

Now, to be honest, I'm a bit lost why you want to work in Illustrator and then bring the image into Photoshop, when you could either place the rendered image into Illustrator and create the clothing there - in which case why transfer it to Photoshop? - or open the render image in Photoshop, and use the tools there to create the clothing - in which case, why involve Illustrator? To get a good fit for the clothing, you're going to need to use the poser image as reference whichever package you decide to use for the clothing, so why involve the other?

JonTheCelt