Just found this interesting but expensive ($499) DIY project. Basically you build your own MSX2 or if you buy an extra component an MSX2+. http://www.ccas.ru/brychkov/gr8bit/

GR8BIT Technical Specifications

Specifications table is continuously updated as more and more devices are being certified for the platform.
Compatibility
MSX2 standard (fully compatible)
MSX2+ standard (partially compatible, full compatibility requires V9958)
ATX form factor
Power management
ATX power management compliant
Software power off function
CPU
Z80 (4-20MHz), compatible or emulation board (3.3V)
Multi-processor capable
Main system memory
1MiB (SRAM), upgradeable to 4MiB
Further extensions to 1GiB (DRAM)
Video subsystem
V9938 VDP, 128KiB VRAM, direct video memory access
Composite TV output (grayscale), RGB NTSC output
Storage interfaces
1.44MiB FDD
IDE HDD
Any compatible storage device in the external slots
Input interfaces
PS/2 keyboard interface (requires keyboard controller installed)
Compatibe keyboard interface
I/O ports and interfaces
Seven (7) GR8BUS internal slots
Two (2) expandable external slots (1 and 2)
Two (2) GR8BUS adaptor boards for internal cartridge connection
Advanced printer port / parallel datacomm port
Two (2) compatible joystick ports / general I/O ports
Multimedia capabilities
3 channel programmable sound generator
Tunable square waveform generator
Additional 5 programmable channels when using SCC
8-bit Covox in parallel port
Networking capabilities (No certified devices yet)
Software (downloadable from the internet)
Language pack (replacement for Kanji ROM, 16KiB). Languages: JA, EN, RU, ES, FR, DE. See "Downloads" section.
Gaming (list, database, more than 320 titles)
Software development (ASCII C, ASCII Assembler, BASIC, Fortran, Cobol, whatever, database)
ROM images (database)
Operating systems (MSX-DOS, CP/M, SymbOs)
Emulation (BlueMSX, OpenMSX)