I can't speak to HSK 1 because I've never done it. Take a look at the word list and grammar for HSK 1 and make sure that you understand everything. My guess is that pimsleur will cover most of it for HSK 1.
Once I had the full Russian I, and wanted to proceed onto Russian II, I think I got it off Amazon (which is also how I picked up my French CDs as well.) Later, when studying Spanish, I stumbled upon the fact that using the site Audible was a way to get a download version. They may have changed, by now, but the only problem with that was you download it and then burn it to a CD. There was no provided way to get an .mp3 file. And then most recently, I discovered that pimsleur.com will sell you the download version (so you can in fact download .mp3 files.)
I have managed to work in some phrases from Pimsleur into in my Skype lessons -- wo bu zhi dao, deng yi hui er, etc. Especially the words that end with "er" as I study a more southern accent in general. Anyway, when I use a pimsleur-leanred phrase I can say it more quickly and "flowy". I guess I should get my teacher to teach more PImsleur style like was suggested earlier, in this thread, I think.
I've never taken any HSK tests, but from what I've seen of HSK1 it's pretty basic. I've also never used pimsleur, but I'd be surprised if after four levels of the program one couldn't do the HSK1. However, I guess that being purely aural/oral, pimsleur doesn't cover pinyin, and you'd obviously have to know that for the reading part of the test (but pinyin is simple enough to master). 2b1af7f3a8