So I want to buy a PS3 (the white or silver one from Japan) but will I have problems using the PSN to download/buy stuff here in Europe? and are there any other setbacks regarding using a Japanese PS3 in Europe?
No, you won't have problems with psn. You can create accounts for any region. I have a launch japanese ps3 and I have psn titles from european and usa stores. The main problem with japanese ps3 models are the region for ps2-psx (ps3 is region free only for ps3 titles) and the blu-ray movies region. Japan and USA are the same region now, Europe has different region.
OK thanks thats not too bad then, but if I understand you correctly I will be unable to play European PAL blu-ray movies on it? that would be too bad but not a show stopper tho.
You can't if the movie isn't region free. There are a lot of movies region free too but not all. For example Fox hasn't region free movies but Sony is near 100 %. If you haven't problems with english is better buy the USA version (normally cheaper too).
I own a US PS3 and haven't had any problems buying/downloading EU content on PSN. I only own two blu-ray movies (that I got for free) - both PAL - and I've had no problem playing them. The only thing I find a bit annoying (not counting no PAL DVD playback) is that the RSS news thingy that displays the latest news for the PS3 is US and I can't change it to EU.
Everything coming from the US gets taxed here big time, since the dollar is low they smelled money or something and nowadays they intercept all coming from the US :/ so eventually its cheaper to get one in Asia/Japan. Also personally I like the silver and white version alot more then the black, and as far as I know these are only available in Asia :/
Not a big deal, I still own verious versions of the PS1 and PS2 lol and even if I wouldn't I really don't care about old games on a new machine. I have never in my life played a PS1 game on the PS2