, if it's only artists you need I would say just build a simple prototype/demo of your rts and use placeholder models (free/stolen whatever just so long your project is still non-commercial). Place it on some sites with some pics and videos (or only pics and videos). Than I think you will have a larger chance attracting modelers/artists since people already see that progress has been made (compared to asking people to join right from the bat).

I don't really see why it is a big deal than to work with GS3d. Stuff like interface can be kept simple with mainly some icons and bars. And graphics can still be good as long as the models and textures are decent. Lots of flashy shader stuff etc. is irritating anyway in rts games (it mostly distracts and makes everything so unclear), just some good hdr and good shadows (and perhaps gore) would be suffice I think. Just keep the camera fairly high with screenies and videos and I think it will do fine with a nice clean and clear graphics style.