So.. after a lot of reading.. a lot of thinking... a lot of experimenting.. playing around and tough decisions.... I have what I think might be the candidate for the actual spectrometer..  This is using the optics I just received from Edmund yesterday.  I have a quick rendering of where the entrance slit, mirrors, grating and detector are in relation to each other.. I still need to fit this into a box that will fit in with the rest of the components..  

But... here's a sneak peak..

Another view....

As always, I'd love to hear what you think!