Not that I am for an Stanozolol only cycle, but if your friend made good gains, then why let someone posting here talk you out of it? I do not think that much pct would be needed.
Anyway onto your planned cycle.
Regarding the D-Bol; I think that 3 weeks (probably 20 days) at 25mg is very sensible and will be very noticable, I always see recommendations of 50mg which is too much. 25mg is perfect in my opinion for your purpose.
The Sustanon would be better off injected every other day at .6ml (which is 150mg eod) or switch to Cypionate 1ml twice a week (Monday and Thursay for example)
Why the Deca, especially on a first cycle? You will not notice what it does to you compared to the Test. Add to that the fact that it will make recovery harder and risk more sides than the test and I’m left wandering why for a first cycle?
The Arimidex would be better off at .5mg every day unless you add something like Proviron, then .5mg eod would probably be fine. .5mg every other day might be fine, but PLAN on .5mg ed.
Taper off the nolvadex.
Make sure that you can spend the time and money on training and food before you start.