I hate to be the bearer of bad news, but you should mount shocks in double shear not single shear. Those top mounts for the front shocks will snap off. This is critical with heavy vehicles. Just a thought. Brackets are readily available pre-made.
http://http://www.ballisticfabrication.com/Coilover-Shock-Tabs_c_197.html
Also: Does the rear spacer have a through bolt? You might check driveline angle and machine a couple of degrees of angle in the top spacer to keep the driveshaft angle correct.
Thanks