Based on RyandGarrison's revised brackets and the newer SmartRapCore files up on Onshape. The brackets should fit within the box (rather than sit on top), allow for printed plastic pulleys around the 608zz, have the removable Z-axis like the newer SmartRapCore + save quite some space on the X axis as compared to the original.
I'm in the process of finishing this build, some things might not be entirely correct yet but it's getting there. Will follow up with more details and build guide once my build is done. See the photo for my work-in-progress.
Also, I used this Ikea 'Eket' box that fits a printer with these parts perfectly. Much better than designing your own enclosure. http://www.ikea.com/nl/nl/catalog/products/20334597/.
Update 8th oct 2017:
I've finished this build some time ago, haven't been able to do a write-up yet but have updated all files and included a ton of pictures by which could should be able to deduce how it's built... Files with a "vX" (e.g. v7) in the filename are designed by me, all others are taken from the projects listed as source (credit where credit is due) but included here for completeness.
In terms of quality I'm quite impressed, I can get very decent quality prints at 130mm/s travel and 80mm/s print speeds at 0.2mm layers. Could probably push it quite a bit further for course prints if the hot-end could handle it.
Update 15th Jan 2018:
Added Fusion 360 source files. Feel free to edit to your liking, but share the results on Thingiverse! Also, happy to say that I can print up to 150mm/s (move 200mm/s) with fair accuracy.. although it will only achieve those speeds on some parts due to acceleration rates (1000mm/s).