I do believe a surpressed pistol and rifle in .22lr would be one of the best SHTF rifles--especially in something that is compact.
I need to search feedback on these pistols (based on atchkinson design)...but they look like fun since they take the 26-rd mags <img src="/ubbthreads/images/graemlins/wink.gif" alt="" /> Put a little 4moa red dot on it and go to town! Hell, even scope it would be fun for hunting squirrels (not sure of accuracy though).
http://www.keltecweapons.com/our-guns/pistols/plr-22/