If the initial prices on 939 boards and chips has you scared off, you might take a look at this roundup of 5 of the more affordable socket 754 boards. Going through the review you’ll no doubt notice the similar performance on benchmarks. With A64, it’s all on the cpu so the board you choose should be based upon the features you want and the manufacturer you prefer.
Quote: “In this round-up we will look at 5 different motherboards from two different chipsets for the 754 pinned Athlon64, the VIA K8T800, and NVIDIA’s nForce3 150 chipset. Four of the motherboards are based on VIA’s solution, the ABIT KV8-MAX3, Albatron K8X800 Pro II, AOpen AK86-L, and ASUS K8V Deluxe. One motherboard is based on NVIDIA’s nForce3 150 chipset, the SOYO CK8 Dragon Plus. Before getting straight to each motherboard, let’s take a brief look at each chipset and what they have to offer…”

Here are some more Motherboard reviews from around the web: