D&D 5E Evasion vs Dexterity

[ZickZak]

I'm creating a build and it will be level 10.
So far I have 6 lvl monk, 3 lvl assassin - even though monk doesn't fit the ranged theme, it is an archer.

We're on a break now and we'll start around when the next book comes out, but unless they add something cool to lvl 1 dip in, (like the new Ranger Ambuscade -.-) I have to decide which class to lvl up 1 more level.

Note:
I am using Four Elements Remastered as my archetype.

Monk lvl 7

• Evasion
• Stillness of Mind
• 1 Ki
• Slow Fall +5

Rogue lvl 4

• +1 hit, +1 dmg
• +1 AC
• +1 Stealth, Acrobatics
• +1 Dex Save
• +1 Initiative

Essentially, rogue gives me much more bonuses, but I'm afraid Evasion and Stillness of Mind is too good to pass on. I'm an elf, so I get some charm advantage, but still...

Thanks for the advice.