I could see anavar being a great option for you, to add to your experience in the gym, making you stronger and allowing you to gain more muscle. The gains will be small and maintainable. You wont get blown out of shape with fluid retention but you will gain good stregnth. Since you are on TRT, there is no need for PCT after. Just cycle your anavar in and out, then continue on as normal. I would suggest around 50mg ED, split into 2 doses, for a total of 6-8 wks. 

Do keep in mind that your gains are going to come from your diet, so make sure that you are getting the right amount of protein for an athlete your size, plus enough carbs and fats to grow