Guessing from your post, there is no specific Megger that you or your boss is expecting to use. Since this is your first megger, I would suggest a couple of things.
Google the term Megger... you will find many links that will take you to great sites for info on the megger units themselves and for great info on how to use the megger and read the results. The site for Megger tools is probably the best for info, as you can download "A Stitch in Time".
It is a classic and still has good info. The site also has other good info on meggers. So does Fluke.
After that, you will be able to make a more educated purchase for you and your boss.