Recommendation for an under sink electric hot water heater?

I would consider a small tank type water heater to be the most reliable type. Depending on the water usage plans, the size could from a 2 gallon compact model which would be sufficient for hand washing or rinsing a few plates, up through 5 - 20 gallon utility models the larger models handling a larger amount of hand washing and maybe even filling a sink, on up through lowboy models of 20 - 50 gallon models, the larger of which could probably do well beyond what you need. Pick your water heater size based on how much hot water you will be using.

As far as electric water heaters go there is very little difference between brands and models as far as reliability. Some (a limited few) such as the Whirlpool Energy Smart Electric Water Heater use temperature controls which are quite a bit different from the rest which would not be available locally even in the US. I would avoid any that do not use the typical thermostats.

Another thing to consider is that despite the smaller size, there is usually not a price break and many small electric water heaters actually cost more than the standard 40 gallon upright models. If you have the space available to install a regular 40 gallon water heater more than likely it will cost less.

I hope this clears things up for you a little bit.