Was considering something like that ... SSD system/applications drive, SSD temp file/scratch file/ACR cache/Lightroom Catalog drive, and 2 conventional or hybrid drives in a RAID 0 storage array.
Building your own rig can be a lot more economical and put the performance in the places where you really need it. I'm in process of building a new photo editing rig right now. Only piece I'm missing is the processor and that's going to arrive in the coming week.
Intel Core i7-3770K Ivy Bridge 3.5GHz (3.9GHz Turbo Boost) LGA 1155 Quad-Core Desktop Processor $295.99
ASRock Z77 Extreme6 LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard $174.99
G.SKILL Ripjaws X Series 16GB (4 x 4GB) 240-Pin DDR3 1600 (PC3 12800) Desktop Memory $89.99
AMD 100-505649 FirePro V4900 1GB 128-bit GDDR5 PCI Express 2.1 x16 Workstation Video Card $159.99
Crucial M4 CT128M4SSD2CCA 2.5" 128GB SATA III Internal Solid State Drive (SSD) x 2 $295.98 ($147.99 each)
Antec Nine Hundred Black Steel ATX Mid Tower Computer Case $99.99
CORSAIR Professional Series HX750 (CMPSU-750HX) 750W Power Supply $149.99
Microsoft Windows 7 Home Premium SP1 64-bit $99.99
ASUS DRW-24B1ST/BLK/B/AS Black SATA 24X DVD Burner $18.99
COOLER MASTER Hyper 212 EVO RR-212E-20PK-R2 CPU Cooler $34.99
One SSD for the OS/Programs, second SSD for the LR Catalog/ACR/scratch. I'm reusing 4TB of WD Caviar Black drives from my prior computer for storage. The AMD FirePro video card will allow me to use my Dell U2711 in 10bit mode for Photoshop (no more on screen banding). I plan to overclock the CPU to 4.2-4.4GHz, which is easily doable.
All this for around $1400, and it will run circles around most anything commonly available on the market right now for Lightroom/Photoshop.