Purely my own preference,
If you already work in aircraft maintenance, Human Factors is something you will already be familiar with (its also the easiest part66 module).
If not, Maths & Physics you should be able to sit having never seen an aircraft, so maybe them first.
Perhaps sit Electrical & Electronics together. And Engines & Props together.
Some modules have a lower knowlage requirement for B2 than B1, and vice-versa. Try to sit all the exams to the highest level, just incase you want to, you know, come away from the dark side later on
