Is there a difference in chargers for American spec or English spec iBook G4?

Only in the physical shape of the AC adapter's in-put; no voltage shift is required

since the device (adapter) is automatically self-adjusting to local voltage input.

The power adapter can use other duck-head shapes, and also the long cord may

be purchased separately (perhaps if not new, in a secondary market) as I have a

few of these. It also is possible, with the long extension cord to have the plug on

the end of it, changed to a local kind of shape. No additional conversion required.

A travel kit may help, so long as it does not change the actual grid power specs.

Good luck & happy computing! 🙂