Hi vnmum, I had pretty much the same with my DD. She used to sleep on me during the daytime, which at first I didn't mind but like you eventually wanted some me time back in the day, along with the fact that she was getting too big to sleep comfortably on me.
Is your DS good at going to sleep in his cot at night? I think this was a big help to me as we had a fantastic bedtime routine, and she was very happy to go in her cot at night. I would say you need to have a set bedtime every night with the same routine before it. Once night is regulated it should be easier to regulate the day, although it can be a bit swings and roundabouts.
I think my DD was thankful for getting her to sleep in her cot during the day as her quality of sleep was suffering. I think I was trying to do too much with her during the day, so I took a couple of weeks off doing anything and focused purely on trying to sort her routine out (this also coincided with weaning, so it was good not to have to faff around with food whilst out and about).
To conquer the day naps I started a mini routine, so that she would learn the cues for sleep as she did for night. This would involve closing the curtains, having a bit of wind down time on the play mat (sounds contradictory I know), then taking off her trousers and putting her in her cot. I was taking my cues for nap time from my DD rather than the clock, so I'd look for yawning rubbing sleepy eyes and general grizzling.
She rarely goes straight to sleep so to begin with I would sit by the cot and put my hand on her chest, and keep putting her dummy in, but would keep talking and eye contact to a minimum. Quite often she needs a little cry before sleep anyway, so thats fine as long as I'm there. Now all I do is sit by her cot until she is asleep, I don't need to have any contact with her at all, and it usually only take a couple of minutes for her to go off.
We also have a sleep raggy that helps, it's like a hanky with a head, but she likes to snuggle into it.
My DD only sleeps for 45mins at a time, sometimes 30 mins, sometimes 60 (and very rarely 90-120). This is fine by me, some babies just need little and often. I tried making her stay in her cot to see if she would go back to sleep but she just got upset. So now her day goes something like this (she is now 7 mo, but has been like this since about 5.5mo):
6.30 (ish) wake up, lay in bed with mummy
7.30 (ish) mummy gets up
9.00 (ish) nap
11.30 (ish) nap
14.30 (ish) nap
16.45 (ish) nap
19.00 (always) bedtime
some of the day naps are flexible, but as a rule she has 4 x 45 min naps a day.
Since spending the time doing this she's a much better baby at sleeping in her buggy when we're out and everyone is a lot happier.
Personally I would start tying to do this asap as the longer it goes on the harder it will be to break. Don't wait for the teething to stop or you may be waiting a long time! and it may make your holiday a bit nicer if his sleep is sorted before you go.
As a final note, I also co-sleep during the day sometimes when I want a nap, and she manages to swap between the two very well.
HTH