First off, I don't own the 350D, I bought is once, but returned it because it was too small for my hand... but here are my thoughts anyways.
$600 for 350D and kit lens sounds low for a brand new one. Is it used? Make sure the online store is legit. There are lots of scammers here in the US, so be sure to checkout the store's ratings at resellerratings.com
I've read good reviews about Sigma's 18-200 and that's probably a good option. Actually if you can buy the camera body only, do that, and buy the Sigma 18-200 with it.
The combo of other lens looks good as well, it's just that you have onver lapping focal lengths.
I wanna bring up though, that the best Canon walk around lens is the 17-85 IS USM. Check it out if it's in your price range.
For sample pictures, checkout
Note that these are taken by regular people, so some bad pics may be because they don't know how to shoot.