I know it's possible to get private registration for .com , .net , .info and .biz, and I think .ws as well, is it possible to get it for let's say .de , .be etc.?

Or perhaps is there an external service that will give you this service, and protect your whois data?

i beg your pardon but what do you mean under "private registration"? Could you explain it, please?

These types are usually country sensitive. For example .de is for German sites, .in is for Indian sites etc.

Christie

A private domain registration keeps your personal information - such as your name, home address, phone number and
email address - out of the public eye.

You have the option of getting a private domain registration with every domain you register. Most registrars charge extra for this service

ICANN, the governing body of domain names requires every registrar to maintain a publicly accessible WHOIS directory for all domains that are registered. This means your personal information is made available to anyone who wants to see it – and it’s available 24 hours a day, everyday. This exposes your personal information to spammers, scammers, telemarketers and a whole host of unsavory characters. A private domain registration can prevent this.

With a private domain registration, Domains By Proxy registers your domain in its name and becomes the Registrant of record. Even though Domains By Proxy is the Registrant, YOU STILL CONTROL the domain.

Foreign domains: unfortunately regristrars do not offer private registration on foreign domains.
(Not available for the following domain names: .us .de .jp .be .at .co.uk .me.uk .org.uk .co.nz .net.nz .org.nz .cn .com.cn .org.cn .net.cn .com.tw .org.tw .idv.tw .jobs .eu .fm .ms .nu .tc .tk .vg)


However some claim that they can do private registration when a customer buys their business registration service at an additional cost.

Hope this helps