"Eso solo" o "solo eso"?

"Eso solo" o "solo eso"?
 

Which one means "just that"? I know that adjectives generally go after nouns so I would assume the correct one is "eso solo", but I believe I have heard "solo eso"

"Sólo eso" is correct. I have never heard "eso solo" before.

Why is it solo eso? Isn't solo an adjective, and don't adjectives come after nouns?

Both are correct.

Both forms are correct, as in "da igual" and "igual da". Joke: A los políticos les da igual la igualdad. By the way, no, it's a common misconception to think that an adjective in Spanish must go necessarily behind a noun. In fact, the meaning may vary. For example:

Ella es una gran mujer [genial] = She is a great woman.
Ella es una mujer grande [enorme] = She is big woman.

A pleasure.