Hey rob, welcome to the boards! you say your looking for a good reliable gun, go AEG simply because it is the most commonly used gun in airsoft. AEG are usually full automatic guns, they can help when you need to take down many targets. Also you said you are going to claybank, some things you might want to know, during the first game there is a ammo reload rule, so bring more magazines if you can, also the game is being played over a 2 day span, so bring some extra bateries. Im not sure how much you know with AEG's, but you can learn most of what you need here:
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YouTube- Airsoft Etiquette (Single Stream)
Gas blowbacks are cool guns and all, but these are used mostly for side arms, like pisols and not as your main firearm. I highly recommend that you invest in an AEG as your primary firearm, and if you want a gas blow back, to buy one for a side arm. simply put.
Also, its not really the quality of the gun, I had no-name ones from wallmart which served me well. See you at claybank. ps what team are you on? better be bravo...