Computer specs needed to boss

Title's not very specific, but whatever. So I've been working throughout my summer in order to purchase a better computer, in order to fight bosses such as Zakum, HornTail, Balrog, etc, with minimum or no lag at all. However, I need everyone's opinion on what specs are recommended in order to do so. My price range for a computer will be around 600-650$. Thanks for replying.

I had almost no problems when I use to (probably 6-12 months ago) do Zakum and HornTail runs with my Dell Inspiron E1505, which has the following:

• Intel Core Duo @ 1.73Ghz (533Mhz FSB and 2MB L2 cache)
  
• 2GB DDR2 RAM @ 533Mhz
  
• ATI Mobility Radeon X1400 (128MB dedicated RAM)
  

If a four year old laptop can handle it, I expect a lot "everyday computing" configurations to be fine with what is currently available.
I've priced components on Newegg and figure a decent build would cost around your price range.

I would expect any new computer to run Maplestory fine. However, two things will halt this:

1. Your internet connection is a huge factor. You could run a 50 GHz Processor*, but it won't mean crap if you have a 1 MB DL rate on your internet.
   
2. Your OS is a second factor. I keep hearing about Win7/Vista issues, so you'll have to circumvent those to boss without problems.
   

*Unholy amounts of processing power there, since a 3.0 is high end atm.

Stay away from Nvidia and vista/Win7 that's all that really matters. As for lag even my crappy Xp comp with 1 GB of ram and an intel integrated graphics card does HT and everything just fine.