I would be worried about what the heat from welding the original bolt holes would do to the metal in the wheel. Certainly this isn't something Enkei intended to happen. Would not do this at all.

Buy what fits the first time. It may be a little heavier but having a wheel that could fail at the wrong time is not worth it.

To me wheels are a consumable item. The lug holes wear out, rims get bent, and wheels crack. I don't have allot of money to waste on something like that so I buy what fit, are easy to clean and service and go with it.