Thanks for the information, errmm... don't really know where should I start from...
Firstly, since you are going to use it for work it must be reliable ( You won't want your project to be lost if your computer hang) I would personally recommend the sony laptop.(Acer are getting better and better though) If we are talking about value here, I would say that Acer Wins hands down. I looked at the specs of the sony laptop and it wasn't that impressive, It has a integrated intel HD graphic and if you are intending to play games like COD6 on it you can forget about it. The acer 4740g has a number of different model, some has ATI graphic card and some has Nvidia 310M Geforce card may I know which one are you looking at? In your case I would advice you to invest more money and get a better laptop though.