I’m going to London & want to bring my hair straightener & curling iron, what exact converter do i need?

Last year I went to London. I actually bought a converter from best buy. It was actually this same one

http://www.walkabouttravelgear.com/graphics/1004.jpg

I took my straightener and curling iron, but when I plugged it in and everything my hair straightener started to smell really strong like it was going to burn or something, so that didn’t work out too well.. and now I’m going back again and want to know the exact type of converter and adapter I need!

I have a Ceramic Tools by Jilbere de paris hair straightener that is 120V AC 60Hz 200W

& my curling iron is a ConAir 120/240V AC 50/60Hz 155W

So what kind of converter do I need for these? Where can I buy one that will work with those appliances?! I’d prefer someone who has had experience with this be the one to answer, but if you know anything helpful I’d appreciate it as well.