What PWM are needed for each LCD Brightness Level

Ok someone here was so kind to sugest ..."the SSC32 (32 PWM channels,
RS232 or TTL control) is $40..." for my LED brake light project.
Someone at the Lynxmotion Support forum said - "Eh, Not really." But
then said I could read the manual to see if it would work or not.
Well, that just exposes My ignorance!! :)
Do all, most all LCD take the same Pulse widfth for certian brightness
levels at the apporpriate voltage/amp level per each LED.
Or, do each type of LED have their own unique PWM/voltage/amperage
ratio for each brightness level?
If I had ANY idea along those lines I would have better idea if the
SSC-32 can do what I need it to do.
The LEDs in question at the moment are 5mm High Flux Red LED (AlGaInP)
with 2 each of these on each channel.

Am I being well too simplistic in my questions?
I would need at least 3 brightness levels Low/Running, Medium/Braking
and High/Attention for several brief flashes not sure if high sure be
the rate high or an over drive.. would be Swell if I could have a
fuller range of brightness levels, but not nessecary.

The 5mm High Flux Red LEDs have the following specs:
http://www.superbrightleds.com/specs/hf5-r5590.htm

absolute maximum ratings: (TA=25°C)
PARAMETER SYMBOL RATING UNIT
DC Forward Current IF 40 mA
Pulse Current(1/10 Duty Cycle, 0.1ms PULSE WIDTH)   100 mA
Reverse Voltage VR 4 V
Operating Temperature TA -40~+85 °C
Storage Temperature TSTG -40~+100 °C
Lead Soldering Temperature (3mm from body) 260C for 3 seconds

optoelectric characteristics:
PARAMETER SYMBOL MAX TYP UNIT TEST
View Angle of Half Power 2ø1/2  90 Degree
Forward Voltage VF 2.5 2.2 V IF=20mA
Dominant Emission Wavelength ÿ D  630 nm
Luminous Intensity IV  5500 mcd IF=20mA

Thanks!