Hi, welcome umpa!
The 320w version is the modified one, and if you get it from anywhere related to homebrew then it should be this version - it's only really if you pick one up elsewhere that you need to check. There are details in the FAQ about the differences, not sure of the ACTUAL power of the unmodified one as never seen one, but it behaves as 400w when heating up and 525w when running for the purposes of the calculator. If you really don't know, run 4 litres of water through it - the modified one takes about 6 hours, the unmodified is more like 3 I believe. Q was right - I am indeed exceedingly clever!

Feel free to let people know where you got it from - seeing as you're new I'll let you know - I don't run a shop and I don't sell anything so you're welcome to post anything and everything that is of help to other people, and any other stuff that is in keeping with the rest of the posts - i.e. anything apart from trying to enlarge parts of my anatomy or sell me pyramid schemes!
You can't actually post images on here in terms of uploading them, but if they are online you can put them in by using the button in the edit box, or if they're worth sharing then send them to jimmy -at- stillsmart.co.uk and I will put them on the site for you - same goes for any reviews, advice, anything else you want to share - this site is for everyone.