Those saddles look very wide to me. Don't be fooled into thinking a wider saddle is more comfortable, it really isn't when you have proper posture on your bike. It's normal to think your saddle is uncomfortable until you've riden regularly for two weeks or something, your ass needs to adjust to the riding. Do at least 300km on your current saddle before you consider changing.
About the bicycle computers, you have to have a damn good bike before a $100+ computer is a good investment. I've seen your bike, you have other priorities right now. I have a $10 bicycle computer, wired, does average speed up to 0.01 km/h, does real-time speed up to .2 km/h, auto stop-start on the timer. The only worthy improvement I can see from the one I have now is to get a wireless one, so the fork is easier to clean without cables running along it.