New Build Issues

I completed a new build for my desktop PC last night. However, I have a few questions. I'll start out with my build though:

Motherboard: Newegg.com - APEVIA X-QPACK-NW-BK/420 Black Aluminum 1.0 w/ ABS plastic front panel MicroATX Desktop Computer Case 420W Power Supply - Computer Cases
Processor: Newegg.com - AMD Athlon II X4 620 Propus 2.6GHz 4 x 512KB L2 Cache Socket AM3 95W Quad-Core Processor - Processors - Desktops
Case: Newegg.com - APEVIA X-QPACK-NW-BK/420 Black Aluminum 1.0 w/ ABS plastic front panel MicroATX Desktop Computer Case 420W Power Supply - Computer Cases
Ram: Newegg.com - OCZ Platinum 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model OCZ2P10664GK - Desktop Memory
DVD: Newegg.com - ASUS Black 24X DVD+R 8X DVD+RW 12X DVD+R DL 24X DVD-R 6X DVD-RW 12X DVD-RAM 16X DVD-ROM 48X CD-R 32X CD-RW 48X CD-ROM 2MB Cache SATA 24X DVD Burner - Bulk - CD / DVD Burners

Used a 160gb HD I already have. My questions:

1. Has anyone seen any adapters that allow 3.5 inch Hard Drives to be used in 3.5 inch external slots? See the attached picture. The area is circled.
2. I'm running Windows 7 x64 Ultimate. However, it is only using 3.50gb of my ram? I'm aware of this issue with x86 builds, but I thought x64 builds could handle all 4gb?

Also, I'd like just some general opinions on the build. The processor is pretty fast. It gets a 7.1 / 7.9 on the PI.