Why take 500mg of sust as well ? he will gain just fine off winny alone ...even a few cycles in I still gained well off winny alone. See alot of people fall into this crap of " you wont gain shit off that" , "you need to stack in this and this and some of that"
he is natural till now so good gains is compared to what he would have gained naturally not compared to what an experienced juicer takeing a gram of test would have gained. On winny alone he'll gain in 8 weeks as much lean mass as he might have in a year naturally which is more then great.
So to answer the question again bro you'll get gains you'll be really happy with off winny alone. First time out keep it simple and conservative you have years ahead of you to try stacking and higher doses if the need ever arises.
Luca