I certainly do not recommend playing Asturias as it is far above grade 7 standard to be honest.
How about Villa-Lobos's Etude No.1? Although many guitar students do not play it properly I think you can display a lot of coordination between both hands in that piece.
There is also Valse No.3 by Barrios. I wouldn't call "fast" per say, but it is certainly one of the faster valses.
Also, if you are talking fast then El Colibri is worth mentioning. It is far easier than it sounds as long as you pick the right fingering for it.
It would help if you tell me what are the other two pieces. A contrast won't necessarily be in the speed.
Edit: Etude No.7 - Villa-Lobos