So I got a response from one of our authorized service centers. It is promising enough as well as daunting. They can order Synaptics touchpad but in case European Acer part stock does not have Synaptics, they will receive Alps. Well, in worst case I’ll have 2 unusable pointing devices (which is not that bad, since sometimes i want to break this crappy device and having a spare part is a plus :) ).

The FRU of this unit is 56.TK901.001, TOUCHPAD BD.SYNAP. It seems that Acer tends not to differentiate these pointing devices. Yes, they are interchangeable, yes, they both work. Yet one of them is superior than the other. The price ranges from $12 to $25 (work is not included) which I am willing to pay to have Alps touchpad replaced with Synaptics one. To be or not to be :) ?