From a technical standpoint, that should work Richie. Practically though, it depends on how well the DVI<>VGA adapters & the mini SLG get along. As long as all three adapters are chained together, interference should be minimal. However the only true test would be to try it out, if you happen to have those adapters handy or can borrow them.
If you are able to get VGA out of your video card directly, that would be preferred with the VGA->DVI adapter as the last piece of the chain. However, I'm guessing from your question that your video card might be dvi out only?