sps, if you must upgrade now, you can at least try the Asus A7V socketA motherboard. It should be amongst the best KT133-based motherboards, and it finally did away with ISA. I have one in my room right now (uncle's new Tbird800 + Asus A7V + Asus GeForce MX combo), but I'm awaiting the cooler before I can test it. I'll report on the results if you wish, namely the Asus-Asus VIA-GeForce compatibility.
Buying Intel now is IMHO throwing money away, in the purest sense of the word.