$64 seems a bit pricey for Socket A. Depending on the features you need, you can replace your motherboard for $30 or so. Spending an extra $30 or $40 is not going to yield any noticeable performance increase.
1) What kind of CPU do you have? Thoroughbred, Palomino, Thorton or Barton? And what is its FSB?
2) Do you need SATA? What about ATA-133? Or is ATA-100 fine?
3) Do you have a video card, or will you be needing integrated graphics? If you have an AGP card, what speed interface do you need?
4) Do you need gigabit LAN or just 10/100?
5) Do you need 7.1, 5.1 or just stereo audio? Or do you already have a PCI sound card?
6) Do you need firewire?
7) Is your modem PCI, or will you need a CNR or AMR slot?
8) Do you have matching DIMMs, such that you can benefit from dual DDR?
9) How many PCI cards do you have? Do you need any extra PCI slots?
Answer these nine questions, and I can give you a specific recommendation.