Sylar only has one power.
I'm not really sure how you can still say that after seeing his origin.
This is how I understand it:
Sylar's original power is the power to understand how things work--hence the watchmaking.
When Sylar met the telekenisis dude, he killed him, and with a single glance at his brain, he could see how to use that particular power.
Think of it this way, we only use 10% of our brainpower. If one person was to use all 100% of their brain, they would know how to do ALL of these powers. It's like knowing how to wiggle your ears...anyone has the brainpower to do it, it's just that not everyone knows how to, and it's not something that you can explain to someone how to do.
Matt just
happens to know how to use the read-other-peoples-minds part of his brain.
Nathan just
happens to know how to use the flying part of his brain.
And so on, and so on.
So our friend Sylar, who wants more than anything to be powerful, has discovered that if he looks at the brain of someone who's unlocked a certain part of it to know how to do something "special", he can then see how that works, and then emmulate it himself.
Looking at the telekenisis guy's brain taught Sylar how to do the same. And now he's on the hunt of every other "special" person out there, so that he can "learn" those powers, too.
Which is why it's so important for him to find Claire, above all others. If he can figure out how to be invincible...well...he'd be invincible in the remainder of his quest for power. I mean, why else would he be so focused on finding her?
Of course I could be understanding that incorrectly...but that's how I understand it, nonetheless.