Conference clothes?

I've been thinking for a while that I need another good blazer, so next month I'm going to do the pattern ~ scissors ~ cloth RTW Tailoring Sewalong.  I have this vintage Evan Picone blazer that I just love:

It just goes so well with everything, it has a nicely distinct waist (I tend to look lost in boxy silhouettes) and it's got nice structure without feeling stiff or rigid.  I really like it for teaching and conferences, because it's comfortable and can make jeans look professional, but since I only have the one blazer, I can't do that look for all three days of a conference or too often in a month of teaching.  So I'm thinking about doing this jacket:

It essentially has the same lines, and I'm not sure if I should stay with three buttons or go down to one.  I tend to like one button cardigans and blazers better than more buttons because I have a short torso and I don't like being all buttoned up, but it might be nice to have some variety.  I'm trying to clean out my stash, so these are the fabrics I'm thinking about:

The pink and the purple on the sides are lining fabrics, and the stack in the middle is the suiting wool.  I have a TON of the black and white plaid on the bottom (something my mother gave me) but I don't really care for it. It's very soft, and it's got kind of a slubby finish, so it reads a little too much like something my mother would wear.  Maybe some of it will go into a pencil skirt one day, but there's like seven yards of it.  The others are a periwinkle, a gray, and a maroon:

I like the idea of the gray best, but I already have a gray blazer!  I think two of essentially the same cut and color would be a little much.  The periwinkle reads as fairly gray in most light, but it's so light in color that I'm not sure whether it would go with my professional clothes.  I like the color of the maroon, but it just seems odd for a blazer to me.  I originally got it for the center look of this pattern:

But I think this pattern reads as more "light coat" than blazer, so I've been putting this off because I already have too many spring/fall coats.  I have this awesome houndstooth:

But there's only a yard of it, and my blazer pattern needs two yards.  The houndstooth might go into this little Butterick Retro vest at some point (the B look on the left):

So I guess the point of all this is that I don't know which fabric to do, and I don't want to buy more fabric (I have an entire dresser and a rubbermaid of stash fabric!).  Is maroon an odd color for a blazer?  Maybe I could get away with it if I wore it with something dark and more sedate.  Help me out, I need to get rid of some of this fabric.