Resources that distinguish btw similar looking kanji

There are quite a few things that do just that. Just search for visually similar kanji on the forums.

There’s a userscript called Niai which expands on the visually similar kanji section that WaniKani already has: [Userscript] Niai 似合い Visually Similar Kanji, this website for looking up similar kanji, homonyms, and synonyms: Introducing Niai: Lookup similar Kanjis, Homonyms, Synonyms and this extension of the self-study script that let’s you study visually similar kanji: [Userscript] Open Framework: Visually Similar Kanji Filter.

There’s also the [Userscript] ConfusionGuesser which guesses which other item you might have confused a vocab or kanji for during reviews.

Also, if you really want to do this you can go to (or another dictionary, lots of them have radical search) and choose the specific radicals you want to look for.

And see @ekg’s answer below for some better suggestions!