I will say this: once you learn your way around the guitar's fretboard, bass will be a snap. But learning how to pluck the bass's strings is still gonna take you some getting used to.

I'd still suggest learning guitar first, though. If you get too used to the heavy bass strings, you'll probably end up pushing harder than you need to on the guitar and having the strings bend when you don't want them to. I always found it easier to push harder than normal when you need to than to pull back from how you normally hold down a string.