Please keep english as the default, at least for the .com domain. Shouldn't be that much work I think.
The wiki is also a good idea, provided that info from there make it back to the main site. But, please do try and do it in english instead of german.
The original amiga-hardware.com site was great. Lots of info, with a simple interface. Since you are now continuing from Ian's work, please try to keep it close to it's roots.
If you need any help, don't hesitate to ask. I'm sure many people (including me - pm me if you'd like) can lend a hand.