Put them up on here, I'm sure we want to see. I'm halfway through a model myself. Patience is a virtue and the best way to get help on the F1T forums is to offer advice and get involved, as well as staying kind and curteous to others. Bumping a thread with a disremark to another member is not the way to go. Sure it's just a misunderstanding. Put the pictures up on here and I'll tell you if i can do anything, although it won't be today, far too busy.
that and 'well that didnt work' in remark to Jordan GP, who i talk to reguarly, and is a nice guy, willing to help others. I know this as he has helped me in the past. I'm not saying I won't help you, but I don't have a lot to work from at the moment mate.
Many months. It's far better to do it yourself. As i said previously, patience is a virtue and the key to success. Making my model a bit at a time, i started in January, I'm only halfway, and i've spent around 15-20 hours working on it. This is a big project, if you're not up to it, don't take it on.
Really google sketchup all you can do is experiment, see what works, and thats the best advice i can give you for the program, however for the dimensions, i would say draw out the max dimensions on each component and build it in that space