Don't get a systema spring. They're really long, and as a result, they wear out faster. My FPS has not remained constant over the last 3 months or so with a systema M130. I'd say get a gaurder. Also, I've heard that the Area 1000 piston isn't that great.
Also, with an M130, you risk cracking the GB shell. It'll probably be fine. But if you want max durability, get an STS.
And don't waste your time or money with a crane stock and 9.6v. Get a 2200MaH 20c 7.4v lipo (a 2200 MaH lipo is more like a 4000 MaH NiMh), charger, power source, and alarm for like $45 from Rhino. Then just put it in the handgaurd. Lipos are a lot smaller so it'll fit.
That would make a pretty sweet setup. Though I'd look at getting a G&P maybe and you'd need fewer upgrades. But if you do go with the TM, you can get a Dboys metal body for like $50 shipped from EBB.