The lowest cost method for the 4x100 conversion would be as much DIY as you can, have to have a bench press available, big socket for the hub nuts, and a bit of time. I paid a local machine shop something like $240 to drill the hubs and rotors but later realized I could of easily done the rotors on my drill press as they are hub centric and the bolt holes are bigger than the studs, meaning they do not have to be perfectly centered to work just fine.
Gun-Runner in the GB listing will do the service for you up to whatever level you wish for very good rates and quality work, new hubs up to assembled knuckles so barely any down time, etc...
There are some wheels in dual pattern, 4x100 and 4x108 but not sure which ones now, not many.
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Back on topic.
The TR FF10 is a great wheel for the money, too bad being discontinued, if I was looking into them I would call Tirerack and ask why being dropped and what will replace them, might be the Kosei though which is a great wheel for the price.