Im searching for a good and cheap host.
I need:
min. 50GB traffic/month
min. 15GB webspace
php4 and mysql and all the other features...

suggestions?

Could you please define what "cheap hosting" is? Are you thinking < $200/m, < $15/m, < $10/m, or < $5/m. The price range you choose can make a big difference on the type of company you are going to find.

You may want to note that I have a data center in Atlanta that gets me pretty good deals on bandwidth, but 50 GB of bandwidth would cost me $110 to purchase. Perhaps this can give you a baseline cost on what you are asking for in bandwidth.

What type of website are you planning on hosting? 15 GB of disk space is huge. I highly suggest you refine your search to either dedicated servers or a co-location arrangement.

I read your post wrong (I thought your GB were MB at first). I have refined my response. Seriously though, you are going to need your own server.

I already have my own webserver with linux red hat.... but the problem is that I live in Germany and a fast and static connection to the internet is so expensive, you cant imagine.

I am looking at working with BroadRiver Communications here in Atlanta www.broadriver.com. They have a facility across the street from the Georgia Institute of Technology (which as one of the first nodes on Arpanet way back when). They fully own their datacenter debt free, which is nice, and they now have a co-sec (sp?) license which means that the Bell-companies have to sell them phone service and bandwidth at-cost. I really like them and they are local to me, but since you are not in the States you may want to look at other companies that are more specilized in managed type services.