I agree, Ittis aren't great for long babies. I also found them very dense, which won't help with the squashing thing. I found Close Parent pop-ins good, or Tots Bots easyfits. They are much softer inside and the easyfit especially works well for long and skinnies.
Both are nice and slim, Close Parent one is probably the bulkier of the two, and because the absorbant parts popper in and out, reduces drying time. It comes in plain colours; pistachio green, custardy yellow and so on. Nice soft cotton-y outer. I find their website really confusing as I can never work out which is the soaker and which is the booster and which is included in the nappy etc., so I would google them and see which stockist has the lowest price!
The Easyfit has a long booster which folds back under itself so you can pull it out to reduce drying time. They have just realised new prints (which are too lush, I want them ALL!) and also in white and they are a one-size nappy, so you can adjust the rise to suit your son. They'll be a good investment 'cos they'll last untill he potty trains. Find them http://shopping.netsuite.com/s.nl/c.427532/sc.7/category.2201/.f
the website is good, and if you do order from them, get some Potion too - it's the best detergent for washing nappies!