I don't think a PTW would be the best choice for a newbie... For a first AEG I would recommend anything by G&G. That way if you break it or something goes wrong you're not trying to repair anything too expensive.
To answer your question broadly, I would suggest;
-G&G M14 (any variant, if you want rails go with the EBR. heavy as hell though)
-2X 8.4v 3800mah intellect batteries (NiMH)
-Hurricane Holosight (model is personal preference)
As for GBB they are much more maintenance intensive. However once you get used to cleaning them and re-lubing them, you will most likely prefer them over your AEG. Not to mention fewer parts to worry about, they can get wet with little to no consequences and they are obviously more realistic.
Those recommendations were not based on your budget though, simply a new airsofter. If you want the high-end right off the bat, go with something like an ARES or Real Sword. Both make beautiful rifles. But if I were you I would stay away from the Systema's for now.
I don't know what you're planning on in terms of gear, but get yourself some good eye protection (I run ESS goggles, they're wonderful) and some kind of BDU and chest rig to carry your real-caps. And with your budget go for some high end tactical boots and gloves.
KWA P226 PTP X2