Sure you can hook up the old Win95 in the short-term. You just won't get the same type of performance with an old HD.
I presume you are waiting until the you get the money to buy a 7200rpm HD?
Just do the ENUM key trick before running the HD with the new mobo. Please remember to delete the key in Safe Mode.
http://forum.pcmech.com/showthread.php?s=&threadid=9254
HTH