Sugest pc configs for 15k-20k for office use

Hello all,
I want to start a small firm which needs 20 desktops and max budget that can be allocated is 20k per desktop.
please suggest configs:


1. What is the purpose of the computer? What all applications and games are you going to run?
Ans:Office work , mainly for programming Asp.net,php , android,dataware house applications.

2. What is your overall budget? If you can extend a bit for a more balanced configuration, then mention this too.
Ans:20K (MAX)

3. Planning to overclock?
Ans:No

4. Which Operating System are you planning to use?
Ans:Windows 7 64 bit (32 bit also ok)

5. How much hard drive space is needed?
Ans:320 GB

6. Do you want to buy a monitor? If yes, please mention which screen size and resolution do you want. If you already have a monitor and want to reuse it, again mention the size and resolution of monitor you have.
Ans: Yes,LCD 15 inches.

7. Which components you DON'T want to buy or which components you already have and plan on reusing?
Ans:there are no components already i have.

8. When are you planning to buy the system?
Ans: next month

9. Have you ever built a desktop before or will this be done by an assembler?
Ans:Assembler

10. Where do you live? Are you buying locally? Are you open to buying stuff from online shops if you don't get locally?
Ans:Coimbatore , can buy online also .

11. Anything else which you would like to say?
Ans:Nothing