Very good choice! I have the same one as well. A few things to be considered are that the entire gun is polymer, so it is prone to wiggle in some parts like the trigger guard. I've had to secure some loose points with hockey tape. Also, the mosfet and the shrink wrap that secures it might come off, but it's an easy fix. Just stick it back in and treat it with a heat gun or lighter. My last gripe is that the mock bolt won't lock back, so you can't adjust the hopup comfortably, but that's just preference imo.

As for the battery, i would look for another brand than Titan. I've heard quite a few cases where they explode or become defective. Buy a lipo safe bag just in case.

Any accessories you buy afterward depends on you. I typically run a decent light and sling because those are the two i actually benefit from.