Following on from Robin, if it was me I would want the bolt through the top mount supported on both sides if it was not tight against the chassis otherwise even with spacers, there will be quite a bit of leverage on that bolt. The other thing to bear in mind is how the shock will be angled when the suspension is compressed as if it's angled over on the build stands it will get worse on the ground and even more so when you hit a bump.
I also ended up getting some rose joint spacers from EDS motorsport on Ebay though they won't completely solve your problem
I couldn't get my front shocks to mount the right way up because the spring cup fouled on the mount arm. Nigel managed with his build even though we both have the same design, which is odd.