Johan....well at least you now know how to handle the H2S issue if it should raise its smelly head again. The smell can also be caused if yeasts are stressed or short on nutrients--so you may want to consider incorporating yeast nutrient into your winemaking protocol.
For your plums... If you have access to Cotes de Blanc or Premier Cuvee you would probably like that, or D47 if you can keep it within its temperature range. If opting to use plums, please consider finding an acid test kit because they can be cause problems on that front, and I think wild plums may be higher than commercial cultivars (or I may have it reversed). Plus, you will have better outcome if you learn how to deal with acids up front. Now, if you have pH meter all you need are the liquid components of test kit to obtain a quick and precise reading.
(Distilling discussion is not allowed here, even if legal where you live--just part of the terms of agreement)
Motto: quel che sara sara