I did the same thing, putting pieces together for the 550 took me a year. Considering it's only $45 dollars for a retune, I would just get the 440 for now since you don't have a US gas tune. I think you could drop this in pretty easy and save some money on 110 then upgrade later when you've got the fuel rails and everything together for the 550.
I watched some youtube videos and DIYs and did the rebuild myself. Need to mark the nut, wheel, and stud to get it lined back up correctly.
Problem with changing wheels:
1. Tune supports the 16g wheel which can max out the MAF as it is, so not much need for increased flow. I would like a billet small 16g wheel for better spool but no one makes small 16g wheels.
2. My intake fits really well with the stock 90 degree elbow on the TD05 compressor housing. Modding rubber elbows to fit other compressor housings hasn't worked well for me and getting a turbo shop to machine the stock housing costs money.