K8T800 or Nforce chipsets are booth good. Asus is a good MB, though I can say I have had good luck with several other brands. Most of the differences between one chipset and another are below what you are going to notice in day-to-day use. Stability is more important, especially if don't have it. IMO, crappy ram and power supplies cause a lot of problems.
Back in the day, some AMD chips ran hot. The XPs and Athlons do not run especially hot set to factory specs, i.e., not over-clocked, The box set chips include a fan and a three-year warrantee (Save the ORIGINAL package), but they can make a little more noise than some aftermarket fans. No CPU chip should ever be started without a heat sink properly installed. Good case airflow is important, 120 mm fans are better than a 80 mm fans, but no fan helps much if you stuff the case in a place with no air circulation.