With ZFS that wouldn't necessarily help. I've been using ZFS at work for many years with mostly large files. Even if I repeatedly read the same file as fast as possible, ZFS will not cache the entire thing in memory (there's no shortage of RAM so that's not it). This is unlike most linux filesystems, which are usually pretty aggressive with caching.

Maybe there is some combination of settings that will get it to cache more aggressively; just saying that it's not a given that it will do so.