Convert your 3.5"/5.25" case bays into 2.5" storage bays.
Vantec EZ Swap EVO (MRK-225S6-BK), for 2x 2.5" SATA HDD/SSD (7-9.5mm height) in 1x 3.5" bay, Hot-Swappable with lock, HDD indicator, Aluminium, BlackR 619
ICY DOCK MB991IK, Mobile Rack, 2.5" SATA6G/SAS HDD in 3.5" bay, with key-lock, push and eject design, Hot-Swappable Inner Tray tray exchangable with MB994, for upto 15mm, Aluminium, BlackR 679
ICY DOCK MB324SP-B, Mobile Rack, 4x 2.5" SATA6G/SAS HDD in 5.25" bay, with key-lock, Screwless Quick Release Button, 1x 140mm Fan with Speed Control Jumper, Plastic, requires SATA Power.R 1,029
Icy Dock ExpressCage Mobile Rack (MB326SP-B), 6x Front-Accessed 5/9.5mm 2.5" SATA6G/SAS in 1x 5.25" Bay, Latch Lock, Screwless Quick Release Button, 2x 40mm Fans with Fan Speed Control Jumper, Active Power Technology, Blue Indicator LED For Each Bay, Metal Case with Plastic Hot-Swappable Bays, requires 2x SATA Connectors, Black, 1 Year WarrantyR 1,209
ICY DOCK MB996SP-6SB, Mobile Rack, 6x 2.5" SATA6G HDD in 5.25" bay with Hot-Swap backplane kit, ideal for upto to RAID 0+1/10/5 in limited space, push and eject design, latch lock, 1x40mm fan with fan speed controller, Hot-Swappable Inner Tray exchangable with MB992, for upto 9.5mm, BlackR 2,109