Hi Fluff, look up Auscitrus on the net. They have great information sheets on the effects different rootstock have on the different citrus varieties.

However, unless you can source a decent rootstock, I'd just germinate an orange or mandarine seed. Apparently, many citrus seeds are clones. Citrus seed loose viability quickly so sow them fresh. You can then graft into them the following year.

Or you can graft into an existing tree, if you have one.

ciao
Karl