I dont know that you would need a Rotary Pump for a Single Group machine? The main reason theyre used in multi-group commercial machines is because of their ability to produce high flow rates whilst still maintaining the nominal brew pressure of 9 BAR. Good quality Reciprocating (Vibe) Pumps are well and truly able to supply the necessary flow rates right down to 1-2 BAR and can easily maintain this at normal brew pressures.
I would say that unless you just want to have a Rotary Pump for the sake of it, stick with the Vibe Pump machines for Single Group home-based espresso production. Theyre a little bit noisy for a few seconds per shot but some Rotary Pumps are also noisy (they can make a kind of high pitched whining noise as the pressure increases) so I guess it comes down to what you want it for in the end :). All the best,