"...I don't think Sun/Oracle ever made an official ARMv5 version.". How about doing some research before assuming this. There is a JVM available at sun/oracle for armv5tel. This JVM runs very well, faster than the others available.
It is able to start a jboss server in 3min.
See
http://www.oracle.com/technetwork/java/embedded/downloads/index.html ./java -version
java version "1.6.0_10"
Java(TM) 2 Runtime Environment, Standard Edition for Embedded (build 1.6.0_10-b42, headless)
Java HotSpot(TM) Client VM (build 11.0-b15, mixed mode)