Of course, there are lots of ASICs out there with exponentially more hashing power. But I'm not yet ready to invest and dedicate to one coin. Is there a mining solution in which one can set up an external GPU enclosure and use those to mine? If so, how would one go about setting it up? Thanks!
You would likely spend as much buying a couple of decent GPUs as you would buying a small mining rig for sha256/scrypt (i.e. Bitcoin/Litecoin).
You can use "riser cables" to connect a PCI-E GPU to your computer's motherboard without it being inside the case but there is a limit on how long these can be (safety / fire risk).. I think 12-15" is about as long as they get realistically.
FYI: GPU mining doesn't need a powerful computer, any old computer will do so long as it has suitable PCI-E ports and a few Gb of RAM.