Where is your friend located? Nebido and Sustanon are not available in the United States. There is one long-term injection available here called Aveed that is like Nebido, but it has to be specifically ordered by a doctor and injected at the doctor's office every time. I am planning to ask my doctor about it during our next visit.
My doctor is pretty conservative in terms of what she'll encourage at the start, because she wants people to find the right dose for them first and then worry about convenience of administration. I started on a half dose of Testim for the first month, then went up to a full dose of Testim for the second and third months, and then switched to weekly IM cypionate injections. She told me that she wouldn't let anyone switch to pellets (which is a longer term method) until they had been on T for a year. So your friend may find that their doctor won't encourage any of the longer term forms of T until they've figured out what the ideal dose is.
FWIW - you will see the same effects and side effects in all forms of T no matter what the method or dosage is. It all largely depends on how your body takes to it. As for the hysto, I don't think it matters when it is done. I know people who have had it done before, and I personally had it done after. When I compare our transitions, I don't see much difference between the two other than the order we chose to have things done in. All the masculinization has been very similar.
