Stupid Problem with Kale... i think!

I started off a bunch of seedlings months ago various different veg in pots/trays, however due to some gardening help from an over eager dog i ended up with seedlings everywhere.

I saved what i could and planted them into the ground but i have some trouble with the Kale, Cabbage, cauliflower and Broccolli. This is my first year gardening and i have no idea which was which so i planted what was saveable and hoped for the best while starting a new replacement set of everything.

These saved plants are now getting quite large, the grayhound cabbage is now clearly apparent (about 6 survived), i think i have 1 savoy cabbage and i have some broccolli/cauliflower (still can't tell those apart, is there a way to tell before the heads appear?are cauliflower lower to the ground more like a cabbage?)

Finally i have some plants which i THINK are kale.

the leaves look like this

http://www.hort.purdue.edu/ext/senior/vegetabl/images/large/kaleleaf2.jpg

Am i correct in thinking kale is the most likely plant?? i only planted cauli's, broc, roundhead cabbage, loose leaf cabbage and savoy cabbage ?? im guessing it has to be kale either that or it's a weed i've missed and allowed to get really big. 

Now these Kale plants are now about 14-15" tall (i have 3) and getting quite big, the thing that concerns me is that the variety i planted where F1 Frosty, who's leaves are supposed to look like this

http://www.unwins.co.uk/images/products/product_1180_large.jpg

Is this right is this how kale matures??

Secondly i've read conflicting harvesting advice?! the seed packet says harvest from january- april, but i've read on the internet that you can use kale as soon as it's big enough as cut and come again??! from about 2-3months after sowing (which is roughy how old mine is)

As ive planted a 2nd set of kale (another 12 plants) because i didn't know which is any of my survivers would turn out to be kale, Im thinking they should provide me with the winter/spring greens i was hoping for.

So im wondering if i could use my surviver plants now as cut and come again to fill the food gap bettween now and when some of my other stuff is ready? because im getting abit fed up of chard and spinach 

Sorry for the long first post but help/advice would be fab

thanks in advance.

I'm harvesting some kale (italian) already. Just a leaf or two from a plant.

Hi there KT and welcome to the site

Yes, both links you have posted are kale and re your cauli question; yes, cauli grows close to the ground like a cabbage, but brocolli grows a lot taller and will form the heads from the centre stem and smaller heads from the 'branches'.

wow thanks guy's

Darn it on the cauli's !!! that means i think all my survivers are broccolli, i've planted some more Cauli's but it means i have too many broccolli and im the only one in the house who will eat it... oh well more for me i guess. 

So when the kale get's older will the leave's look more like the second picture? 

Do you think i should start harvesting the surviver plants now? there's only 2 of us in the house who will eat it and i don't think i'll need 15 plants come spring!!! 

Also forgive my stupidity, but i know when you harvest you take the outer leaves? and new leaves grow from the centre, doens't that mean you end up with a really long empty stem and leaves at the top eventually? like a big umbrella? also if i keep harvesting depending on growth, how long will the plant keep coming back before i should think about pulling it up?? (making plans for the space haha)