No free lunch, last time I looked at doing this it was a bit of a ballache, hunt for the exactly compatible parts(sometimes even matching firmware versions) then jump through a good few hoops to get it up and running and then something updates in the background and it all comes crashing down.
Good for an offline system perhaps but not your everyday computer, unless I suppose you have time and patience to baby it from time to time, or making images of the Os drive regularly would avoid most calamities.
Have they managed to make a nice hackingtosh laptop with decent specs using an off the shelf laptop?
If I remember correctly it was virtually impossible due to some hardware incompatibility of some sort that is unique to most laptops.