Make a box for all your watercooling gear and put it either under or on top of existing case:
like so
Or if you must fit it into case then it'll all fit in your Thermaltake I bet. The XASER3 is same internal design as
the XASER 2 I have. There are a few rivets on the front of the frame that hold the hdd cage support in place. Drill them out to remove the bottom hdd cage. Then you
cut a hole and can fit your heatercore np. Put 2cds in 5.25s (space for 2 more) put 2 other hdds in top hdd cage, take floppy drive and throw away (and get a USB thumb drive)
I guess you could use floppy until you get 2 more hdds though