The hardest thing to source is the Bleach.
Adorama will ship smaller sizes of Flexicolor Developer/Replenisher (you dont necessarily need to use the SM version) but of course they are out of both types and the Developer starter also.
You just need to watch their site because they don't have a "notify when in stock" option like B/H does. If you see they have the products, dont delay because the stuff gets snatched up these days.
I feel your pain because it took me a month to figure out the best strategy and I eventually resorted to eBay for an off brand Bleach that ended up being a decent deal.
I did just receive my RA 4 stuff from Adorama in the 10L sizes so we'll see how that goes.