Not napping at 7 months old? Poor mommy and poor baby! It sounds like he does need the CIO method -- from my hazy memories, we had to do it after each illness or family vacation -- though it wasn't always dramatic (sometimes 45 mintues, usually more like 13). Our guy is 20 months old now and we still have to let him cry on occasion (though that's part his personality -- being held animates him rather than soothing).
My idea would be to try CIO at naptimes -- in the Healthy Sleep Habits, Happy Child book (incredibly poorly written by an arrogant doctor, but some good ideas), I think it suggested doing the bedtime routine (minus bath) for naptime, then letting them cry for up to ann hour. After an hour, get them up if they're still awake, but try again the next time he shows signs of sleepiness.
It sounds like he needs to learn to put himself to sleep, both at naptime and night. As for the standing, I would go in at 10-15 minute markers (give him a chance to learn to get down, but give him a break too!) but not talk other than muttering "time to sleep" and actually yawning. Show him by your actions that it isn't time to be awake.
Good luck. Sleep is so important for everybody!