Pro/Forums - quick-disconnect shutoff valves

I am building a watercooled system. I'm not interested in extreme
overclocking; I am just trying to build a system that is dead silent, high
performance and stable. I'm using one of the Intel Harpertown CPUs, the x5482;
one of the reasons I'm using a Xeon processor is that this permits me to go
with FB-DIMM memory, which, in turn, means I can run computations that need
large amounts of memory, plus I get ECC on my ram.

I'm cooling things with a big passive radiator: an Aquacomputer Evo 1800.
I'm also using water blocks on the GPU, to eliminate needing a fan there.

As is probably obvious, this kind of system is not the kind of system you see
gamers typically build. It is not really "extreme." I'm not focussed on
getting the last degree of cooling or the last megahertz of overclocking out
of my system. I just want to cool fast parts, operating at stock speeds, down
to reasonable temps, and I want it to happen in a stable, quiet way, so I can
get back to what I like doing with computers, which is hacking code. Thus the
passive radiator; this is also why I'm using 3/8" i.d. tubing, and am choosing
waterblocks that don't require high flow to work well (e.g., a Swift GTX for
the CPU). The writeups I've seen on the net, by Cathar and others, are fairly
persuasive on the subject that you don't need a gushing Niagra through your
system to cool it reasonably well.

I found, with my last watercooled system, that doing work on the system after
it had been constructed was a real pain, due to all the water lines. I even
watercooled the hard drives on that system, for sonic isolation.
Unfortunately, this makes swapping a failed hard drive out of a RAID a major
operation -- it's somewhat analogous to the stories about oil-changes on
Ferraris requiring the mechanic to remove the engine from the car. This is not
good: modern hard drives pretty much require you to plan for failure.

This time around, I'm trying to tune the system for ease of maintenance
and hardware upgrades; maintenance includes biannual water changes. So I am
considering breaking the water loop up into modular segments using
quick-disconnect shutoff valves, such as the Koolance VL3-F10S, VL3-M10S and
VL3-MG parts, shown here:
http://www.koolance.com/water-cooling/?cPath=60
I am aware that this will add extra restriction to my loop, but, again,
that's OK for my design point.

The water loop for my system naturally breaks up into these components: (1)
pump, (2) motherboard blocks, (3) gpu card, (4) radiator and (5) reservoir.
Even if I don't break it all the way down into five segments, it is
particularly handy to be able to easily disconnect the loop at the pump
output. I can use this to flush & refill the system, which I will handle with
a big, loud, outboard AC pump (a Danner Mag 18) and a filter -- I can easily
splice these elements into the system via the quick-disconnect connectors if,
for example, I want to blast Pine-sol through the loop, or cycle in new water.

So, here's my problem/question. I'm trying to set up the system using the
convention that the upstream quick-disconnect connector is male and its
downstream mate is female. This would make it easy to insert & delete segments
from the loop. But Koolance quick-disconnect shutoff connectors don't offer
all connection options. You can get *male* connectors whose other,
non-quick-disconnect end is (1) barb, (2) G1/4 thread, or (3) compression
fitting, but the *female* connectors only come with compression fittings -- no
barb or G1/4 thread. This means, for example, that I can't screw a female
connector directly into the intake of my radiator, reservoir or GPU
waterblock, which would simplify the setup as well as lower restriction.
(I.e., the alternative is using a G1/4 barb fitting on, say, my reservoir
intake, then have a short length of tubing running to the female
quick-disconnect connector.)

OK, that's Koolance. Maybe someone else makes quick-disconnect shutoff
connectors that come in a wider variety of flavors. I went to the
McMaster-Carr website at www.mcmaster.com, and here I was defeated by their
catalog. I couldn't make sense of the various offerings; I am insufficiently
expert in this sort of thing.

So I thought I would turn to this forum for advice. I'm looking for a
family of quick-disconnect shutoff connectors. Lower restriction is
better, of course. Both the male and female connectors need to come in
variants that can be connected to G1/4 threaded holes as well as 3/8" i.d.
tubing, either by barb or compression fittings.

Can any experts make some recommendations?

Thanks!

-Olin