The LPD8 will VERY QUICKLY get limited in Traktor. Do you definitely need to have Traktor if just doing it for pleasure in your home? Just asking as it's a more serious/pro software and there are cheaper alternatives. Just asking the questions!
I use a VCI-100 as main controller and LPD8 for the sample banks, which is a more realistic setup. To expect to control Traktor with only a single LPD8 is a tad unrealistic in my opinion. Plus, it'll soon get boring with not many buttons, knobs and faders to use.
My advice would be to get a proper MIDI controller rather than the LPD8. Something like the Hercules RMX is very good controller for the price if you don't want to stretch to a VCI-100 and will work much, much, MUCH better with Traktor/Virtual DJ than expecting to use an LPD8. I think you may even get a copy of Virtual DJ (though not as good as Traktor but an alternative if not too serious about DJing - though I've seen many established clubs using Virtual DJ!) with the RMX too, and if only a hobby it has a built in sound card so that is all you would need and would be your only financial outlay.
Cheapest place I could find it new was here:
http://www.yonies.com/pidD.asp?chk=1...ixers&rf=frguk