I've been looking up and down, but I can't seem to find the stats (Cost, modification slots, availibility, etc) for a lot of the modifications listed in Arsenal, under "Military-grade Armor Enhanements". Many were restatements of various cyberware pieces, and they said so in the description. However, there are many (such as the flotation system, mobility upgrade, quick release, and strength upgrade), which have no stats whatsoever, or at least one that I can find.

Am I missing something, or are there genuinely no statistics available? If there aren't what would you do?

The book has them in a table at the bottom of page 51, and in the compiled tables in the back on page 182.

I'm AFB at the moment, but if memory serves the PDF version was missing the listing in the main entry, but I'm pretty sure that the listing was there in the compiled tables.