I think the Tex with it's standard metal case might get a bit too expensive, especially considering shipping and custom fees.
If you go for the Tex, the Pure Pro or the Filco Minila you're going to have trouble finding new keycaps. Keyboardco offers a blank set for ISO, but I think it's ABS.
Honestly, it doesn't take too long to adjust to a one row enter, and I use the key above for delete which is very handy, if you want blank caps I guess you're able to touch type, so I would recommend you to get an ANSI board and just use it with German layout, you then are not going to have problems getting custom caps and have a bigger amount of keyboards to choose from.