Depending on which you go with (there are plenty of cases you can pick in between those prices) you will have enough for a Cooler in case you Overclock. The motherboard is USB/SAT III and Crossfire capable so in future if you want to add a second 5770 you can (likely not needed until you get a 1920 x 1080 resolution screen)
The i5 750 is an overclocking beast, I believe some get it to 4ghz stable.
1920 x 1080 is a nice resolution, but it is not important, just a nice to have some time in the future, if you are happy with your current resolution there is no reason to buy another monitor at all - if you were using a 1280 x 768 or something I would say get a new monitor, but yours is a good resolution.
Also, I know I gave www.scan.co.uk links despite your preference being ebuyer and overclockers, I just used scan as it is a site I tend to buy all my parts from (except RAM) so I am most familiar with it, but you can buy from anywhere you want.
The reason I went with a PSU more powerful than you need is because
a) It has a £15 discount so is a great buy for a good quality PSU
b) It gives plenty of room for you to Overclock your system and run two 5770s.
c) You can probably get away with using it if you build another computer in a few years time (assuming your next build was only using one card)