Experts Please Advise

I know this is an overclockers zone but I believe no one else can give me a better opinion. I have been going through hundreds of reviews, tests etc and they all confuse me

I am looking to build a good system with following requirements

1. Office Purpose, mainly Adobe PS, Indesign and heavy multitasking. Have over 10 Word Files, Adobe PS, Adobe Indesign, PDF files open at the same time which requires frequent Alt-Tab

2. Play Latest games at 40 plus FPS at 1680x900 at MAX Settings

I have selected the following specs. Please let me know if this is good enough to handle my req. or should I need to work on my specs again . I AM NOT INTERESTED IN AMD

1. CPU Intel i5 4570

2. 8GB Corsair Vengence (Should I go for single stick or dual)

3. Gigabyte G85 Board

I have an old 9800GT card PCI 1.0 or 2.0 and 400 Watts supply. Will later upgrade to a Nvidia 660ti or 760 ti may be 6 months down the line. Please suggest since I am on a tight budget

1. heavy multi tasking: better go with an i7 (4790k)
2. 16GB would not be luxury in your case
3. what board is it? You could go with an Asrock Z97 Extreme 4

What is your PSU brand? If no name, get rid of it and grab a quality 450W.

Regarding the GPU, as you plan on upgrading in 6 months or so, wait and see what will be available.
At the res you game, any upcoming mid range card will do the job.

Honestly the specs you recommended would be way beyond my limited budget. My budget at present is USD 375 for a Processor, Board and RAM. I could add another 50 if required

You will want 2x8GB of ram... a quad with HT. If you are not overclocking, than a B/H based board would be fine.

What brand PSU do you have? Also, in 6 months when you upgrade your GPU, I wouldn't do so with those 'older' cards, get something from the 9 series midrange when they are available. Way more power efficient and powerful.

Im wondering how productive you really are with such a tiny resolution/single monitor. Sounds like you need some more screen area...

I am using a Corsair PSU. I am left with limited options since i5 series does not support HT. Can you recommend something around the range of USD 200 for a CPU

For your uses, I would save another $100 and get a CPU with HT personally. If you can't, you can't. You have a good (only) choice for the budget picked already.

Thank you