The iMac wins everything except for not being able to run the LaserWriter and the scanner and the RAM. Get a cheap RAM upgrade and a FireWire to SCSI. If the LaserWriter has Ethernet switch to that or use AppleTalk to Ethernet bridge. You can part the 7300 out a bit to pay for the extra stuff, that sonnet G4 will sell for example.

Even though the 7300 has a G4, the iMac's bus is twice as fast and the CPU is 50% faster, it will beat out the G4 in all real world performance.