one of the best is autodesk or Auto-CAD
www.autodesk.com
but u have to be very good in that stuff, do use them.
and without a graphic tablet you wont get very far.
check them out, i tried a few of them, but have to capitulate.
its realy for professional use.
check it out, but i dont know if theres a trial version or something.
anyway give it a try