Changing Cherokee for a Smalltalk based web server?

Hi all, I'm getting random "504 gateway error" answers from several sites (using Zope and Rails) that are served by Cherokee using a reverse proxy setup. This error is an open issue in Cherokee and has been reported and not properly patched since 2009: https://code.google.com/p/cherokee/issues/detail?id=504 I did choose Cherokee because of its easiness to setup and newbie friendly interface and character, but with this problem I'm thinking in testing another server, may be a Smalltalk based one that have similar characteristics and can serve sites in Zope or Rails also. I know about Comanche, Swazoo and Zinc, but I don't know which of them is better (making load balance and stuff like that) and have proper documentation about using it in combination with other software (Zope and Rails in my case). Any advice on this matter is greatly appreciated, Offray