YEs DC01 is very reliable, the DC04 models are also reliable.
In my opinion, the DC01 models to the DC25 are the best. No other.
A Dyson DC07 with the later cyclone will be suitable because you hardly need to wash the filter, it rarely gets dirty! This is only for the late DC07 models.
Also, the Dyson DC07 and DC14 are the most powerful Dyson vacuums ever made! They have the most suction, and they stick to the floor well. Especially the non clutched models.
The most reliable Dyson DC04 in my opinion is the Silver lime model. They has the good and reliable Italian Ametek motor fitted to it, which is why you dont see many burnt out DC04 lime models. The clutch DC04's do have a good motor, but not as reliable as the DC04 silver lime one.