Darth Avlectus

Can't go wrong with a tektronix. 100mhz should cover anything you'll be wanting to look at.

If you're not using the power transformer to try and isolate crazy high voltages, yes, it will do the job just fine. Really, the only difference between a normal power transformer and an isolation transformer is the insulation between the windings.

(Also make sure the secondary in the transformer is taking the voltage to where you're wanting it, but you probably already know this. )