Lens and Camera Choices

Hi everyone, I'm new to the forum and new to digital photography, though I have used an Eos film camera for years. I recently bought a P&S compact to dip my toe into digital waters, and have been delighted - digital has kindled a big fire in my belly, and I am now ready to go SLR.
I have chosen the 20D based on what I have read and how it feels in my hands in the camera shop. I have also decided to take the basic lens kit, but also want to get something extra-special and this lens choice is giving me much more of a hard time to decide on. I have followed the threads and various stickies for a few days before posting this, so I am reasonably aware of the various options and opinions going around.
I'm planning another trip to the camera shop to see if I can 'get a handful' of the 2 options I am most interested in - but their shelf stock is not that great so I'm not sure how successful this will be.
My first choice is the 17-40 L - but I am a little concerned that it is neither wide enough nor long enough on a 1.6 crop. Also how handy is it as a walk about lens?
My second choice is the Sigma 24-70 2.8 EX DG macro - but it seems to be about the size of a house brick.. The range seems ideal for a walk about, and as time goes by I could get wider and longer lenses.
I can only afford one or the other. I would love a 24-105 IS L but they are still real hard to come by in the UK. And I can't bear to wait any longer...
Thanks for any advice,
Steve

Well 17-40 is equivalent to 27-64 mm in old 35mm terms. So your previous film SLR experience should tell you whether it fits the bill. I'd say it looks pretty good for a walk-about lens on a 1.6 crop.

I love the 17-40mm but have resisted getting it because as a single solution it is neither wide nor long enough on a crop body. It's personal. I'd rather have wider and/or longer. Good idea to get the kit lens as that can fill in nice enough as a widey stopped down and then I think the Sigma is a very good choice. I had one and it is a good lens. It is heavier than some and not so heavy as others. It balances well which is what I noticed immediately I used it. I prefer it to the other mainstay at this range, i.e. Tamron 28-78 2.8, because of the build and width. The other option is the Canon 24-70 L, but if you don't want to spend on the 24-105 IS L (my first choice) then that is in the same ballpark.

Welcome BTW

Both are worthy choices: personally I'd lean to the Canon.
All the lenses on your Wish List more or less replicate the coverage of the kit lens, and all will outperform it by a country mile. So why bother with the kit lens at all? Most reviews say Canon got the cost against performance balance skewed with this one.

I'm sure you're right about this, but the extra £60 to get the kit lens is so little extra that I think I prefer to have the lens - i am sure it is no worse than the 28-80/28-90 lenses that ship with most film cameras - so should be Ok for what it is.
I don't really want to get any other EF-S lenses - till I have decided how I feel about crop factors anyway, and I would prefer to be able to sell the camera on with its kit lens in the future and keep any decent glass for the next model..
I am definitely leaning towards the Canon 17-40 , the more I read and hear the better it seems. L fever striking? Probably! but in a couple of days i'll get to check it out in-store - then decide!
Steve

Optical performances are pretty much on a par, but you''ll find they are significantly different in your hand. The Sigma is heavier, noisier and you have to both flick a switch and trombone the ring to allow manual focus.

For £60 I can see why you would get it. I also got the kit lens with my 20D. It ain't a great lens, but it ain't a bad lens either. I would suggest you consider one of the 24ish-70ish f/2.8 lenses. With the 17-40L your fastest lens is going to be a f/4, not really fast. Let me mention that the 20D's fastest and most accurate AF mode only comes into play with a lens of f/2.8 or faster. I got the 24-70L when I got my camera and later sold my 'kit' lens when I picked up the Tokina 17mm f/3.5.