Need to prepare Vegas project for DVD. Files are either too large or colors become too saturated/dark.

Sony Vegas Pro 11
DVD Architect 5

I've made a video in Vegas and need to have it put on a DVD by tonight(Needs to be ready for tomorrow).

I've searched through tutorials and read up a bit on Vegas/Architect, but I run into a couple problems.

1) If I render as "DVD Architect NTSC Widscreen video stream", the resulting MPEG-2 is of noticeably lower quality. Specifically, the colors are darker/more saturated looking.
2) Rendering as an AVI (HD 720) makes it look perfect, but the file is way too large (Half way though I ran out of disk space and the file was 40+ Gigs)

I appreciate any fast responses since I'm on a deadline.
It is a video slideshow.
20 minutes long