Also, if possible upgrade to NetBSD 6.
Well, my goal was originally to upgrade to 6, but because of all the issues I am having I am still trying to upgrade from 4 to 5. Are many people using NetBSD 6 on port-amiga?
I have to say that NetBSD 6 runs very, very well on my Amiga 1200 with 256 megs. I can even compile stuff which requires more than 64 megs of memory at a time. I highly recommend skipping NetBSD 5 because of how much has been fixed.
Another thought is that if Apache is too heavy, instead of nginx, perhaps you should try the NetBSD built-in httpd?
Also, if you'd like a kernel and userland compiled with your config file and with -m68060 to avoid trapped instructions, I'd be happy to compile the tree using one of my 8 core machines.