I recently passed an '05 Sonic blue GT with light blue stripes. I have to admit, I didn't really care for it. I went for the Black and Blue (wonder if there's something there Freud would like to comment on:tongue ). I didn't like the stripes but went for the Mach 1 look. You can see pics in my gallery.
I don't think you're going to see enough difference between the sonic blue and vista blue. From what I've been able to tell, it's the same blue tint with a larger metalic flake. The sonic blue is more of a pearl.
How about some of the color-changing clearcoats? I had thought of doing ghost flames in them before settling on the Mach 1 look. If you really like the stripes you could go with a dark grey.