though the link's helpful i would make some suggestions:
1.) Go for the AMD config (in the upto Rs. 20000 section)
2.) You can reduce the RAM to 1GB
3.) I suggest you go for an LCD monitor (17" Viewsonic). these are catching on & are low on electricity consumption, can be moved around easily and take less space. should stretch your budget by just 3 thousdand. if you don't buy one now, you might regret it later.