It would be far cheaper and less hassle to buy a pillerless bluebird.
You would probably need doors from the pillarless anyway as the windows would be different.
Not to mention all the work you'll need to have done to the chassis and floor for extra strength as you will be loosing a lot by removing the pillars. Will need a way to sort out body roll etc...
Your going to need real deep pockets to make it work, that is if you are intending on doing it properly (engineered etc.)