xbox and ps2 are old enuff to have established games for their pc's
yet ps2 has a wide range and variety
since u are opening a game parlour ... u cant possibly keep all the games
u have to have certain KEY games .... like say NFSU ( for sure) , quake 2 even ( just cuz im a fan

)
unreal tournament .., counter strike, doom3
now most of the games are available only on one platform ... so i guess ur deciding factor is the games u want to keep
theres no point as far as i see in keepin a combo ... unless u reaallllyyy want some games that are there in the other console ...
so look into this ..before u make a decision ..
as for ur pc setup ...
extremely high end pcs are definitely not required. .. instead get more no. of pc's ... otherwise urs would be a "small" pc multiplayer environment if u know what i mean
im sure htere must be multiplayer cafes in nagpur too ... each having a min. of 10 pc's ... even tho u have the added attraction of ps2's/xobox's ... i suggest u compete with them in every aspect to play safe if u know what i mean
this is just my opinion .. but since u are venturing into the unknown i think u should consider all facts/possibilities ..
xbox2 no ones heard much abt
ps3 isnt gonna be anywhere ard before end 2k5-2k6 ... MINIMUM !!!
for ur needs ... u dun even need a good soundcard ... since u cant have speakers everywhere
ull need a good set of headphones ...( the studio style ones )
so onboard audio will do on ur pc
as for the graphics card u can go for 9800 pro .... 256 mb version ..
and go in for amd 64 bits ...
each pc for less than 40k is a good choice ... 9800 pro will ensure compatibilty with games uptill doom3 ... in good resolution/frame rates ... with most eye candy on ...
since ur going in for it commercially i dunno if u should go for ps2's with mod chips ... they will allow u to play pirated cd's as well .. but like i said since u are gettin into it commercially this is gonna be a very big risk factor for u .
again this is just my opinion but i would really appreciate u giving it some thot ....
last but not least the idea is very exciting for lack of a better word .... and i would love to have helped in some way
take care ... best of luck .. and cheers m8
PS: would love to see those snaps