Lenses question for HD Video

[Howitzer]

Getting a Canon 650D soon.

Keeping in mind I'm a bit of a novice when it comes to camera equipment I have a choice on lenses:

A single 18-135mm lens OR an 18-55mm & a 55-220mm lens.

The majority of my work will be HD Video, though I'm edging into photography too, hence the DSLR.
Which of these options should I go for?

I am guessing the main advantage in video would be depth of field on the subject? Would the quality of separate lenses be better than that of a sinlge wider-ranged lens?

Any advice would be much appreciated

Cheers!
Howie.

 

[Howitzer]

I see.

I'll check to see whether the 18-135 is STM. Though if I get an external mic later on it will matter less. I'll have to think on that.

Thanks both for the help