First off I would like to point out that the video link you provided is a great example of terrible film making.
The quality is bad, as well as the actual film work.
So like TimStannard already said you will likely have no trouble replicating that and yes iMovie should be sufficient to edit if you set the bar that low.
If you already have an iPhone I too would suggest using that in combination with something like a tripod, especially since you plan to edit on Apple hardware as well.
If you want a little more control there are literally hundreds of cheap low end camcorders available that will be able to produce a better quality than that video link you posted as an example.
Is the video you want to shoot for your own business or do you want to shoot video as a business?
If it is the first you are better off spending the $800 to hire a professional or even a semi-professional and they will be able to get you a video that greatly surpasses your example.
If it is the latter I would personally:
•start with getting a DSLR that shoots 30FPS HD (preferably one by a brand that has a lot of affordable lens options as well like Nikon or Cannon)
•get a zoom lens and a prime lens with < f 2.0 for low light conditions
•get a good tripod (not a $15 one)
•get(or build) a decent desktop for NLE editing
•spend a lot of time practising with your equipment
•learn to use a more professional software program (like Adobe Premiere/After effects, Sony Vegas, Blender or Avid to name a few)
The cats are watching us...