550 lens requirements for my needs suggestions?

[AussieBrent]

Hi Guys

Just wondering if anyone would like to recommend a couple of lens for me I am having a tough time deciding which ones to get.

I'm not to fussed about price but I wouldn't like to go over $1000 for two lens which I feel is what I require.

I currently have a 550d just standard lens kit I am looking at upgrading I really want to focus on taking pictures of :
Landscape
Beach
Bush
Seascape
Street
Rivers/streams
Anything really outdoors.

I'm thinking of for landscape pictures the 10-20mm Sigma 4-5.6 which is $435 via *removed, members with less than 50 posts cannot discuss/name commercial companies - refer to the site rules*

Anyone like to recommend a walkabout lens for say general photo taking or if you think of a better lens for landscape feel free to suggest that as well.

As I said happy to spend about $1000 for 2 lens if required.

Thanks