I need to control 25 groups of 3 LEDs or 25 RGB LEDs. Each group will be dismissed from the uC by up to 20 cm (about 8 inches). 20 cm is very safe assumption but I think it will be 10 cm or less.
However, I think If it be even 5 cm, it will be hard to create in matrix way, so I think using MAX7219 likie IC (http://www.arduino.cc/playground/Main/MAX72XXHardware) is not best idea.
I will probably use shift registers (http://www.arduino.cc/en/Tutorial/ShiftOut). I can connect multiple 74HC595 or use something like STP16C596.
I prefer STP16C596 but they are obsolete. I found SCT2026 (http://zefiryn.tme.pl/dok/a04/sct2026.pdf) but I'm not sure is It right choice.
One more note. My current project requires only "2 bit control" over each group (3 LEDs off, or selected and turned on only one of them), but I don't think it make my project easier or cheaper, also controlling each LED separately will give much more flexibility in case of changes.
What solution will be fit best for my requirements.