Give the dual stage regulator thread a read on my web site from LeftC.
Plenty of specific discussion and many post with pictures etc for the DIY person seeking top of the line CO2 equipment.
I use dual stage Victor regs, you are not going to get too much better, ebay often has good deals. Stick with dual stages.
Valves, Ideal and Swagelok are both good, I like the Swagelok and have 1 ideal as well to compare, not much difference really. I use vernier caliper adjusters on the Swageloks, makes keeping track and adjustments very precise.
I use most Tygon tubing, soft and thick walled.
See ebay also.
Gas tanks, local fire place sells them for 50$ filled and stamped for 5 years and refills.
Clippard solenoid valves are good, reasonable priced.
Reactors, diffusion methods, I use mostly needle wheel type. What good is a high grade CO2 without good diffusion and mixing? I use disc in high water flow regions in some tanks, I like the look I guess.
That + good high current in my tanks to mix the CO2 well.
Check for leaks etc a lot at first.
Save yourself about 100-200$ this way, get the best stuff, and know where and what each part does. Takes time etc to learn and all, but I think it's good if you are into using CO2 and plan on staying in the hobby a few years.
Should last 20-50 years also.
Regards,
Tom Barr