sorry to say dis but i m not doin b.tech.
1st of all why p4 why not AMD its far more superior den p4 at dis point of time.
config for AMD
3000+ (939soc)-7k
MSI RS480M2 mobo-5k
256mb ddr ram minimum.(corsoir,kingston.)-1800
80 gb sata seagate hdd-dun kno da exact price.sum where around 2700
CD-RW Sony.
15'' flat samsung-5k
cabinet-which ever u like-1000
logitech keyboard and optical mouse-1000
modem(int)-300
speaker not more den 500-700 as budget is already goin high.
ups-TVS or APC.
all dis will cost u around 28000 i know its 3k more den ur budget but dis is really sum wat future proof.u can eva play latest games as MOBO has da on board ati x300 grafix.but if u dun wanna spend more den 25k den u can go for 754 socket so it will b in ur budget.but dun go for p4 trust me its not worth it betta go for AMD any day betta den p4 at dis point of time.
and yaa do temme if u wont b able 2 push ur budget for 3 k so dat i'll b able 2 telu sum other config.