Honestly, you'd be better off getting something other than an SP marker. SP is a terrible company, but this isn't the main reason that you should stay away. I'm not 100% sure about the SP-1, but the Ion is a pain in the dick to take apart. It'll take you about 5-10 minutes just to get the bolt out to change an oring, and probably longer to put it back together. Not only that, but the marker is Ion threaded, so if you ever wanted to upgrade to anything other than a Shocker, or a Luxe, you wouldn't be able to use other barrels.
Honestly, this really depends on your budget, and what you already have. If you already have a good mask, hopper, and air tank, then I would recommend getting a Quest. You can find them used for around $200, and it is by far the best marker for the price. If you don't have a good hopper/mask/air tank yet, I would suggest buying one of those first.
Hope this helps!