Hi,
have this HOWTO successful implemented. I know what you mean. The long time load of bootwiz is normal because it just reinitialise and creates the version.ini etc. But that is the point. Just before loading bootwiz the first time (like described in article) you must reboot your system and afterwards open the bootwiz and then you see the winpe4 successful installed.
In your situation you just must start at the point in the article beginning with "copy version.ini" to waik folder etc.
And stop your SBS Services. If not, you are not able to copy the new sbs_x64 folder.
Hope this helps.
Regards