I doubt they'll ever re-print them. But I do have all fifteen of them, and overall they're very good. At least I enjoy them. I see them in used bookstores sometimes, and you can find them online if you look.
They are regular novels, not "Choose Your Own Adventures". You can find more about them here
. (And probably several other threads, too.)
What I'm looking for (and am in the midst of collecting) are the French junior novels. The Random House series was translated into French, and when the series ended the translators wrote about six more original stories. The ones I've found so far are interesting, but it's a lot of work to understand the muddled mess that comes out of Google Translator.