Apache is slow and FastCGI adds even more overhead. To speed it up you usually tune the kernel, sysctl.conf, use SSDs add a nginx-caching proxy infront etc. But this is usually overkill.
We know Chicken-Scheme is close to the speed of C. That's why I think that creating a platform such as erlangonxen.org, an nginx module, or using a development environment such as gwan.com would yield in much more performance than anything you can get with Apache. But I understand that Apache is very widespread and "easier" to setup.
hmm I didn't try it and don't know if it works, but maybe Chicken Scheme can run on G-WAN without extra efforts. Worth a quick trial and error experiment :) I believe that you can ask the author for adding that language, if it doesn't already work out of the box. He has added support for many languages so far and adding another language shouldn't be a problem except that it may require patience.