One thing to consider is to have your rig sized for most of your gigs and then for bigger ones that are not frequent, rent some racks and stacks. This way you don't have the $$ tied up in gear you don't use often and you don't need to transport it too - for the big gigs get some help to move the rental or have it delivered.
Another advantage is that the client gets good sound which increases your chances for more work.
Eventually you will need to own the bigger gear but by then you will have auditioned lots from the rental house.