I am looking laptop so i can play Starcraft 2 on at lest medium or better yet high. I have 900 dollars. I was thinking an i5 or i7. 8g ram and a dedicated GPU. the hard drive does not to be huge 500g would be fine. I dont know if i want a 15 or 17 inch screen so could you give me ideas for both or tell me which one would be better. I am looking at these two:
Neither of those two laptops are particularly good options.
The biggest reason is because they have 15.6" 1366x768 displays and 17.3" 1600x900 displays. Low resolution displays such as these limit multitasking and productivity because they make everything onscreen large, and they tend to have terrible image quality due to low contrast. I recommend against this type of display to those who have a budget that allows them to get a laptop that has a better display and at the same times suits their needs, and who don't require larger text for eyesight-related reasons.
Secondly, you can do better than a GT 540M for your budget. It isn't a terrible GPU for your budget, but there are better options out there.
What appears to be one of the primary alluring factors for you is that some of these laptops have Core i7 processors. But for gaming, certainly with a GT 540M but in the general case as well, your primary bottleneck is going to be the GPU. Unless you have a particular need to have a fast processor, your priorities should divert towards the screen and the GPU before the CPU.