Ned Han

Hi all. Got my hands on a td05h which looks to be in very good condition. Can't hear any noise or feel any movement. It's a front entry turbo but has all the markings of a genuine unit so I'm confused as to what it actually is or what it's from.
Im sure this has been covered many times before but what are my options for changing the compressor housing and wheel to 18 or 20g?
where can I get such items and how much is it likely to cost to get balanced?
thanks