My favorite dictionaries up to now have been:
Canon
Casio
Sharp (the screens are very good).
Many moons ago the Casio had a stylus which worked well with the Kanjigen but this would mean that you were proficient with written kana(explanations of the Kanji were in Japanese). I still have a preference for a Canon, but the Casio comes a close second for me. I will have to take a look at this Nintendo option as it sounds intriguing. As an aside, there are many software programs for translation available (although I don't know if this will be of use to you).

Cheers.....