>Specific reasons no, just an interest in the branch of languages they are in.
That's great! Both are equally as interesting and once you learn one, the other becomes much easier to learn.
Note that the alphabets for one another are different.
> I believe Assyrian Neo Aramaic has many many dialects, and as these languages do not have the most resources
We can hook you up with some resources. I know /u/AkkadiNamsaru has some good resources.
> I'd go slightly paranoid not knowing the dialect I'm being taught with a certain text, unless they are not that different?
What do you mean by certain text?
Both are similar but are grammatically different. Turoyo (Western Syriac) and Eastern Syriac (Assyrian Neo-Aramaic) are much similar than Syriac is to Arabic so learning one will make the other really easy to learn.
The only differences between the two languages is: the alphabet (slightly different way in writing the letters) and the grammar of the language. Words in Turoyo are extremely similar to words in Eastern Syriac.
There's also an app on the play store called Learn Assyrian which is a really good intro to learning Assyrian.