What timer can I use?

I need a timer and I was going to buy a normal 13A timer but I looked on a hydroponics/growlights website and it said that normal timers can't handle the power load from HID lights, and that I would need a 2-switch bypass timer or something. I don't believe the website because if I'm using a 250w HPS thats 250w/240v which would mean there was 1A going through the timer so I could use 12 of these lights and STILL be fine with a normal timer. So why does it say I need a special timer? Will I be alright with a normal one?

I have a wal-mart digital timer hooked up to 400 watt hps, and 2 stanley blower fans
no problems.

Good, thanks. I thought they might just be trying to rip me off.