yes it sure will be sufficient for your casual riding. i have a citizen tokyo and love it. it is one of the best bang for your buck bike. it is sturdy (steel frame) but quite heavy although i see that you will not be doing any bike lifting, nifty and gears work ok too and when i fold it it is so small in size. you can check CL and sometimes they sell folders for a decent price. i got my tokyo for about $100 at CL (and it's one of the wisest investment i had). i also was able to get a used dahon boardwalk D6/7 for a decent price. if you want to get a brand new bikes, they only sell citizen's online. some here on the forums have used citizens and they might be able to fill you in. but if the cost is of essence, then citizen are a way to go and you'll love it....
thanks,
vic