I think Apache (or httpd) should work fine on Efika for CGI as it really doesn't have much CPU load for low traffic CGI pages. So should MySQL as long as you don't to very intensive operations.
But if you want smaller web servers then lighttpd & nginx are both quite small and do CGI. There are some packages like tinysql etc i think which you can search in the ubuntu arm repositories (using the add/remove software menu in your MX)
Pl note that I am yet to try these out on Arm - waiting for my MX to arrive today or tomorrow. But i have tried them earlier on very low power CPUs like Via 500Mhz and they work perfectly fine. Plus they are available in Ubuntu Arm Repositories.
I am sure some experts will pitch in in a few hours with more accurate advise to help you with this.
Meantime you can read these links:
http://en.wikipedia.org/wiki/Comparison ... eb_servers