I really wouldn't worry about which class to take. Both are important. Too bad you don't have time to take both (assumption). Networks might be more "practical" if you're applying for a job at Cisco. Logic might be more practical if you're applying for a job at Xilinx. Both would be practical if you're applying at Google. I would suggest that you take the one you're more interested in. Personally I would choose the networking class, and it might be more applicable when you start hacking at your startup... but take logic if you like it that much. Don't waste $$$ on a class that you're not as interested in -- especially when you have the luxury of choosing between two CS courses.

Also - don't stress over it. It's your last semester, you'll have the rest of your life to learn whatever you didn't learn at Uni.