I think you should stay with the 4427 (it's non-inverting) that I mentioned.
Right, the Arduino outputs connected to the INA or INB will switch the corresponding OUTA and OUTB. VS is the +12V (that'll be available at the OUTx pins.)
For path to Ground, you could stay with the transistor circuit. Or you could use a ULN2803, no resistors necessary between their inputs and Arduino outputs (they're set up in the IC.) You didn't give me a current spec (don't leave me to go look up this stuff on ebay, just put up a link, preferably the manufacturer's own, OK?) - the ULN2803 has a considerable VCE(sat) at higher currents.
"SMD 131" == 130? ?
I think that 3 White LEDs in series is about 12V of VF.
I'm thinking that this will require a supply > 12V (15V ?) to do right.
So, as you have access to a string of these, then:
what's the voltage across the LEDs and what's the current at the intensity you find satisfactory?