The one in post #9 is the dog's danglies and has half press AF.
If you'll never want a variable self timer, or to queue up multiple exposure over time, or to set a timed long exposure (without staring at a stopwatch), then that one is overkill, but I think worth the extra fiver for future proofing in case needs change. It does not need batteries in order to operate as a simple two stage shutter release, only to use the timer functions.
The one you linked to originally obviously has the bare minimum spec. If that's all you'll ever need then I'm sure it will be a fine choice. Of course, if your shot timing is not absolutely critical then you could do quite well using the 2 second (or 10 second) built in self-timer (combined with mirror lockup) to release the shutter without risking camera shake.