[necron2600]

Solaris 10 install DVD alternately doesn't work or takes a million years to even load the boot kernel on my Blade 2000

boot cdrom - text (note the spaces)
You need to install via text mode anyway if you want your root filesystem to be ZFS based vs UFS. (unless newer Sol10 resolved that, I forget)
At least you may be able to see more of what is going on during boot.

You can also boot cdrom -v (verbose). There are other arguments to use as well.

If your SB2000 has a bunch of PCI ethernet cards.. each one can take several minutes before they timeout during the initial install process as it waits for DHCP responses.

Bad media?