You'll be surprised at how quickly you'll make the gains back by just pumping the iron and eating.
My advice would to be, run something you're used to... (I mean, I'd honestly suggest doing it naturally for a while.)
Save the Tren for when you're back in beast mode.
I actually took 6 years off the gym lol.
Pumped natural for 9ish months.. ran a cycle.
Thrn 3 months after, ran a second cycle.
Back at full size.
The cycles were light and easy, nothing crazy.
The before and after pics for a year and a bit ago VS now, are fucking insane.
EDIT
Now that I'm back in the swing, I'll be running a Tren cycle in the fall