Robert one option until the arrival of the SPARC bootable iso (soon ??) is to use the procedure described at the links below. This will install a minimal build 125 on a SPARC system. You can then point at a repository and install extra packages and image-update without the need for wanboot support.
I have successfully used this on a Blade2000 which does not have wanboot capability. Not supported, but really the only option at the moment without wanboot. Cheers Frank http://alexeremin.blogspot.com/2009/11/opensolaris-sparc-snv125-livecd.html http://alexeremin.blogspot.com/2009/11/installing-opensolaris-on-sparc-using.html
