I would def. stay at the 200mg Tren A for your first cycle with Tren. My first go with it was terrible. I started with 200mg per week and all was good so I upped it to 300mg per week and then to 400mg. By the time I hit 400mg/week I was losing my mind. I got really insecure and was super angry. It's no longer an issue running 400+mg/week for me but the first time around was ROUGH.
Also, be prepared to sweat like a MOFO at night on Tren.