Nope not a muppet. Its just a long learning process. I am sure everyone who has been around a few years will have made a number of mistakes or bad choices on their systems.
You will still be able to complete but it depends on what sort of comps - simple DB output, SQ etc (Not really into the comps any more and don't know the various classes)
Even if you don't do well you can use it to learn where the weaknesses are in the system and improve on them.
If you are spending proper money (and it sounds like you are) make sure your installers know you want to complete. This way they will make sure they won't cut corners just to save a few quid and they should also get pics etc to help show insulted cables etc etc.
I am sure with the system you have its going to sound very nice.