I'd personally shy away from e-machines.
The cheapest way to a hot PC is usually to put it together yourself. They make it so easy these days. It's about as complicated as piecing together leggos.
Also, keeping specs in mind, it may seem like an e-machine is hot as they advertise P4, 2.4GHz, but they don't tell you that it is the older P4 with the 400MHz fsb (the new ones are twice as fast at 800MHz). Also they probably put in PC2100 RAM instead of the newer stuff.
If I were you, I'd keep my keyboard, mouse, monitor, modem, CD, and floppy, and put them into a new case, with new motherboard, CPU and memory.