hey its awesome to hear you want to start getting into freestyle and park riding! however there are some things i should point out. first of all freestyle skiing is not really something you can try out and see if you like.... i mean of course there is a first time for it but you really can't judge it on that and you have to stick with it and progress with it to really decide if you want to stick with it. next with the way the ski industry is going and the way skis are made now have you considered selling your skis and buying a pair of all mountain skis? something like the line blend, k2 kung fujas, armada arv, 4frnt msp, volkl bridges, or anything else like those would be awesome for everything park, pow, and groomers.... im not very familiar with your boot but my guess is its a downhill boot and its pretty stiff. if that is the case i wouldnt worry to much about it until you decide you want to stick with freestyle skiing but if you decide you do then you may want to look into replacing it, and if it's more of a flexible boot you should be ok..... so you are approximately 6'0 and 165 pounds, you should probably look at anything from 175cm to 185cm, if you do decide to get an all mountain ski rather than just a park specific ski you should probably not mount at center, rather a couple cm back. if you do get a park specific ski you should probably mount them at center. there are also some good cheap park skis like the line invader for instance....its cheap as hell and holds up especially if your just starting out..... i did some research and found this website http://www.valthorens-skishop.com/indexgb.html it has some shops at val thorens and has links to their websites (might be somewhat useful).
also this is kind of off topic but you might find it useful. when i used to live in garmish partenkirchen, germany a couple years ago they had this shop called Conrad Sport. they had really good prices and gave my dad deals all the time. i looked around and found their website http://www.sport-conrad.com/index.asp i dont know much about the euro anymore and dont really follow currency values but i know belgium uses the euro so it might end up being fairly cheap for you, and depending on where you live in belgium i cant imagine shipping could be that much.
anyways its been a long night for me so i think its about time i go to sleep i hope this helps you out, good luck!