15k including monitor, table and chairs? That would be hard specially you chose e7200 for your proc.
I suggest you go the AMD way, cheaper but reliable & stable, and would perfectly meet your needs. Buy a motherboard that has onboard video like Asrock-many features for the price.
Monitor? Hmm, try to find second hand monitors here in buy and sell.
Memory are very cheap these days, so go for 1 2mb pc800 kingston brand.
For the casing, whatever suits your style just make sure it has a 1 120mm fan intake and another 1 120mm fan exhaust. Look for a case that both side panel can be opened and there is space to hide you cables at the back of the motherboard tray. Achilles casing would be a good choice.
You would be ok for the generic psu, just be prepared to buy another one just in case it will die on you. Buying a 2k+ branded PSU is too much for your budget.
You could defenitely squeez everything in the 15k budget, just dont expect too much performance in gaming and other applications but it would defenitely get you through.
For the chairs? a gas lift is very comfortable but I have no problems sitting in a monoblock!