It seems to me that everyone has misunderstood Georgie's question so far. He is asking if "gell" rhymes with "eh". (Although it seems he is also asking if "gell" means the tag question "eh").
This sounds like a slight misinterpretation of Austrian pronunciation. In Vienna, at least, the "gell" is pronounced "gö", or in a similar fashion. People only seem to pronounce it "gell" if they are talking to children or trying to be especially articulate for some other reason (e.g talking/shouting to deaf old people).
e.g. Des hot s' oba obi g'haut, gö? (That knocked her over, eh what?)
Mir san eh olla per du, gö Schurli? (We can all use first names, eh Georgie?)
Und jetzt gehen wir ganz brav in die Schule, gell Kinder? (And now we are all going to school like good boys and girls, aren't we children?)
Oma, nicht die Leute mit dem Gehstock hauen, gell? (Granny, don't whack the people with your walking stick, eh love?)
I have heard the "gö" sounding almost like "ga", and some foreigners pronouncing it as "geh".
The polite form is: "gön S'" It sounds like the English "guns" and I must say I felt a bit threatened the first time I heard it ;-)