O2 Cylinder Sizes - What are people using these days?

I'm looking to develop a standard O2 cylinder installation for the
HP-24 sailplane kit, and I'm curious what size cylinders people
generally have installed these days.

These days a lot of folks seem to be using EDS systems which seem to
offer very good efficiency at turning pressurized gas into blood
oxygen. So less pressurized gas is needed than back in the old days
when we were all using surplus A8A regulators.

This webpage lists what seem to be the the standard O2 cylinder sizes
these days:

http://www.mhoxygen.com/index.php?op...t emid=50#pdf

The cylinder sizes I generally see referred to in forums like these
are these medical sizes:

D-size: 4.4 in/11.1 cm diameter, 18.7 in/47.4 cm length, 14.7 ft^3
volume
JD-size: 5.3 in/13.3 cm diameter, 18.1 in/46.0 cm length, 22.8 ft^3
volume
E-size: 4.4 in/11.1 cm diameter, 27.0 in/68.6 cm length, 24.1 ft^3
volume

The information I'm looking to collect is, what size cylinder do you
actually have installed, and does it generally meet your needs?

Thanks, Bob K.
http://www.hpaircraft.com/hp-24