I really liked my Altaros, when I had it. But, you're going to want to give it more air flow than the minimum requirements. The more, the better. Otherwise, you'll be running your first stage at it's maximum capability every time you use it for this. What I liked about the Altaros over the shoebox was that it moved slowly and did not generate a lot of friction related heat while working. I've never owned a shoebox but, I've read about some of them needing extra fans to keep cool. What I don't like about both of those systems (after owning one) is that you have to have 2 machines running anytime you need to fill. Which doubles any chances of something breaking. You also need more hoses and fittings which can get a little messy if not done right. They're a nice stepping stone to a stand alone.
Stand alone compressors are coming down in price. For a few hundred more, you might consider the new liquid cooled Omega Trailcharger that works off AC/DC power ~$800. Also, the Hatsan spark compressor was impressively small ~$550! Air Force had one as well. It's reportedly, ultra quiet but is a long, slow fill and maybe more suited to filling overnight ~$800.
Whichever route you take, make sure you include a desiccant system to keep the air going into your rifle/storage dry!
Good luck!!
Tom
