2 nics
 

can i have 2 nics in one linux server with the same ip, so that linux can user 2 * 100Mbit
eg. 2 * 3c905tx with the same ip and linux has a connection with 200 Mbit?

yes, it's called "channel bonding", There's a driver that comes with the kernel.

See the /usr/src/linux/Documentation/networking/bonding.txt file if you're keeping your kernel source in /usr/src directory.

Or try a search for "channel bonding" on google.com