I wouldn't feel comfortable telling you exactly what to do because there is a lot to know, but perhaps someone else might. For one, Cutler recommends ALA AFTER the metal body burden has been decreased or eliminated, as ALA pulls from the brain and you don't want to pull metals from the brain into an already overburdened body. This requires either DMSA or DMPS alone. Then, later down the road ALA is added.
As for IV vs. oral I would go with oral... IV is too risky IMO. I had 1 intravenous EDTA treatment for lead and was set back for months and months. But, I also consider myself on the 'heavily' toxic end so others may fare better.
A wise recommendation is to start SLOWLY. If followed properly the protocol is relatively safe. There are some risks - albeit downplayed as 'minor' - but that's why it's important to know as much as you can beforehand so that you're informed. It'd be great if you had a Dr. to guide you through all of this but finding one who follows the Cutler protocol may be tough.