You really can't go wrong with Tippman's. I owned a .68 carbine as my first marker, 16" ceramic barrel and I could shoot more accurate than anyone on the field.
I had that for about a year then some guys wanted me on a team (which I ended up captain) so I needed to upgrade gear.
The cocker is stock except for:
WGP Hinge Trigger (Eclipise makes a nicer one, but I was broke at the time)
Bomb 4-way valve
Sticky Grips
Upgraded bolt for better air delivery to the ball
Black Ice regulator
It's a quite low pressure gun, it took me a lot of hours of tinkering to get it to the point where it was reliable, the speed was actually adjustable and the timing was fine. On a 68 cu in tank at 4500psi I can shoot damn near a case.
Anyways, I'd say Tippman as your first marker. They are as simple, reliable and idiot proof as they come. If that doesn't suit your fancy, I'd say a Piranha. I've used these in some handicap games (NPPA guys vs Amateurs, Amateurs get to use their regular markers) and found them to be very reliable, simple and quieter than a spyder. A spyder barks like a dog and has a funky sound to it when fired, I don't like it. They're good markers for some, and some swear by them but I never was one to like them.
The most important part of your new setup will be the barrel. I had a 16" ceramic on my first as I mentioned (I wish I could remember the manufacturer) and it fit PMI Premium paint perfectly. My J&J Edge system has several sized bases to get a good paint-to-barrel match. Another note on tippmans, they are HPA (High Pressure Air, or "Nitro") ready. So you can buy the marker, use C02 until winter, pick up an HPA tank and use that. When the time comes to upgrade, you can sell the marker only and you will already have a good HPA. That's handy for spreading costs out over time.
I haven't been to sleep yet and its 0630 EST so if this doesn't make perfect sense, my apologies. Spelling errors I apologize for in advance if I have made any.
