Hi,
I think the a) set is not bad. The others have a lot of stuff that you probably not need at the moment.
It all really depends on what else you want to do, or if you fancy doing some other pojects in the beginning to learn more about the Arduino.
Relay looks good to me, but since you are in Israel, you may find a similar relay in a local electronic shop or from an israelian distributor?
I do not have any experience with wifi shields, so maybe read around what other projects used. The shield will go on top of your uno and take up some pins but as you only need one additional pin for the relay switching this will not be a problem at all.