First off, your right with the sidelight bulb number, they are 501 but I would strongly suggest avoiding LED lights, regardless if "CANBUS Error free".
2ndly, I can't rightly remember what the bulb number for the DRL's are (Something like 7220) but they are W21W (Wedge fit, 21 watt).
and finally, every car from around 1998 has canbus. Its just a fancy way of connecting each ECU to eachother with only one (Or 2 in some cases) wire. Saves alot of wiring, can you imagine the size of the loom if it were otherwise (Engine ECU, ABS/ASR ECU, Dials ECU, Body ECU, EPS ECU, you get the picture).