Sergio, <-- always liked that name by the way!
Adapters; looks like the s6 fills using a probe. Make sure the gun comes with the probe and further figure out if the probe is threaded or a quick attach style probe (has the quick attach end instead of threads).
Not to derail your pump theory or budget, but do you have any local dive shops or nice guy fire stations near by? If so, I would buy an SCBA tank and use that to fill your gun. It will be dry clean air and far easier on a guy for refills. I like the sense of having a pump as a back up, but I have only used the pump one time in the course of 6 years. No matter what direction you choose, plan on buying something else in the future. I now have my own source of air at my house simply because I had a vast distance to go for a refill on a scuba.
I would also recommend a range finder. You don't need anything that an engineer would need just something simple. You typically won't go out past the 100yd mark for hunting. Screwing around I have stretched a couple guns to 150-175 but nothing further.
Last but not least, a stockpile of pellets

. I've owned my impact for less than 2 months and already have in the park of 2000 pellets down range. Never shot any other pcp as much as my impact. The gun never fails to impress, well, except when I miss...