Depends on what you plan to do mainly... woodsball/sup-air?
Do you prefer the good-ole feel of pulling a proper trigger or would you not mind using an electro-marker where you can barely feel the trigger?
Electro starter marker - go for an ion
Mechanical/scenario starter marker - go for a tippmann - custom 98 if on a tight budget or an A5 if you can spare a few extra £££s