Can you include a PC power supply, at least during the prototype phase? They give you 5 and 12V. The other option is to buy a 12/15/whatever supply (eg laptop chargers are usually about 19V) and then use an LM2596 module (about $1-$3 on eBay) to produce your 5V.
I think the 7219 includes current control so you probably don't need current limiting resistors for any of the outer ring. You will definitely need resistors (1 per chain) when using the 6B595.
Riva: not really. The 7219 will drive only one maybe 2 LEDs per segment, not the 10+ required for these big digits.