What do the lights do? Animate in any way or do they just flash? Do you need to control every single LED?
So you have any 5mm LEDs on hand? Do you think they will be bright enough for your purposes?
You can buy small WS21812 prewired matrices that are very very bright (and you can of course dim them down to whatever you'd like) and you wouldn't have to deal with a bunch of transistors and a whole lot less wiring.