Speaking as a physician, I will decline to suggest any specific tests. However, I will offer you these observations. Before ordering a study of any sort (lab test, imaging, etc), a good clinician already knows two things:
1) Why s/he is ordering each specific test; and
2) what s/he is going to do if a given test comes back abnormal.
So I would suggest that, before you shell out a lot of money 'shotgunning' labs (the term of disparagement used to describe a poorly-thought-out set of lab/imaging studies), make sure you have a very clear response to both of my points above. Best of luck.