Invisalign with acceladent is a great solution
Invisalign will allow you a a nice cosmetic result while maintaining your professional look. acceladent is a newer technology that allows you to speed up tooth movement by 40 -50%.. I use it in my practice and my patients are thrilled with the result
Your pictures are great and helpful. While invisalign could work, your best solution would be lingual braces on the top and either lingual or clear on the lower. This is a more expensive option than others, but will achieve best results and be truly invisible. The best lingual braces are custom made pre-programmed. They take a 3D CAD of your teeth, move the teeth to the desired end result with virtual software and then fabricate custom made brackets and wires with robots. It's space age technology. A good clinician who cares about his patients and getting the best results should have a 3D cone beam scanner in his office to take virtual records. Check out the following sites for more info: imagingsciences.com, dolphinimaging.com, and 3M iBraces. I think that will give you a good idea and a lot of information.
And don't let them slenderize or "reproximate" your teeth (sand the enamel between them) it will shrink your arch and face and could lead to problems with TMJ later.
You do not have to spend 1-2 years with traditional braces. Removable appliance like invisalign could easily correct the crowding and in much shorter time.