Welcome to the world of pump, I'm not new but not a old member. I think the first thing you should decide is whether you want to play open class (tank, small hopper) or Stock class ( horizontal feed tube usually 12 grams). Well if you like your cocker, you could turn that into a pump for pretty cheap. You can find pump kits for your gun ranging from $35 to $100 all day long. The only down side is it will be big compared to phantoms and carters but then on the flip side it is a cocker and parts are a plenty.
Their really is no bad or really good pump. You'll see that most (IMO) people use open class guns such as snipers or CCM guns. I just bought my Series 6 today
. I'd find some guys in your area that will let you shoot a pump before you decide on which one. With you being use to that cocker it shouldn't be hard for you to stay with it.
Oh and down call playing pump "playing down" it hurts me...