WHAT FLASH

im off to tenerife on friday. and may have a look for a flash gun whilst there.
i was there in dec and picked up a sigma 105 macro 2.8 for £116. so hoping i can pick up a cheap gun.
apart from the canon 580 and the sigma super , what else should i look for.
are ther any other makes apart from canon and sigma that i could go for, and are there any makes or model numbers i should avoid.
i have a eos 350

I just bought a Phoeni x[COLOR=#333333][FONT=​Verdana,Arial,Helvetic​a,sans-serif]DZBIS-112CII of off ebay for $99 and I like it so far. I've really only used it for snapshots and at a birthday party, and I still have a lot to learn, but I'm happy with it so far, especially considering the cost.

Here's the link to B & H, but it's on ebay for $99 here in the US:
http://www.bhphotovide​o.com …ghType=category​Navigation

a canon 420EX or 430EX would also be good.

Canon 580 if you can afford it (it's the best Canon makes), the Sigma EF-500 Super if you want power, features, and can't afford the 550EX, and the 430EX if you don't need quite as much power and budget is a bit tighter yet.