I don't think all part of CS5 and Lightroom is multi-threaded. Although this link is based on the older generation core i7, hyper-threading didn't matter with lightroom (2.4 x64) http://www.anandtech.com/print/2837
You have to see if the ~$100 is justifiable. If photo editing isn't a career or anything near that importance, you don't need the i7-2600k and that the i5-2500k will suffice. The hyper-threading will be good for a little future-proofing and if you do have the wallet for it. I will not stop you
As for the sound card, don't purchase it yet. Check out how your onboard audio sounds first. Onboard audio has made leaps and bounds you know. I wouldn't go with OCZ.. I'm not acknowledged about SSD but I heard some things about OCZ and their fail rates. Be sure to check the reviews first. If you can, I would get the crucial m4 128 ssd for $208: http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Thanks winter. I will do a bit more revewing on the ozc ssd and on ocz overall.
I am in Australia so getting crucial has been a mission to locate online or in store. its not something i have seen regularly in australia.
hopefully it will serve me well for the next 5 years as this will be the last system build in a long time