Reddit mentions of Raphael Kolinsky Sable, Watercolor Brush, Fine Point, Series 8404, Round, Size 02

Reaper triads all the way.

There's no non-wasteful way to put paint onto a palette from a GW pot and it's also hard to mix GW paints in consistent proportions between sessions. GW paints also tend to dry out in storage and there's always some amount of crust around the lip of the container.

Reaper Master Series on the other hand has none of those problems plus with the triad system you don't even really need to bother mixing paints in the first place. RMS last longer in storage (I just took mine out after a year of being in storage) and I can easily just put two tiny drops of paint onto my palette and mix with an equal amount of water. I also like the "play" of RMS paints too; they tend to flow better off my brush and I just think I get better results with them.

But the biggest advantage I found with RMS is the time saved not fucking around with mixing colors, dealing with dried out pots, and not cleaning a shitty brush used to load paint onto the palette.

In your shoes I'd buy a triad of each of the following:

• red, orange, yellow, blue, purple, green, gray; that's 7 colors with 3 shades of each color so 21 paints
  
• pure black, pure white so 2 more paints
  
• brown triad for dirt, brown triad for leather / clothing so 6 more paints
  
  Then two each (one dark, one lighter) for each of the basic metals:
  
  
• silver, gold, bronze so 6 more paints
  
  I also find it handy to have a pinkish tone and a pale or linen-white color so possibly 2 more paints there
  
  If I can do math correctly that's 37 paints at ~$3 ea so a ~$121. I order my RMS directly from them and was very happy with my purchase. If you know for a fact you won't be doing any green then don't buy it, but from experience the primary and complementary colors, two lines of browns, greys, metallics, pure black, pure white, a pink, and bone coloured white are always useful.
  
  I also highly recommend each of these:
  
  
• Raphael Kolinsky Sable size 2 Despite owning ~8 Winsor Newton S7 brushes, another 8 or so Raphael brushes, and half a dozen Rosemary & Co brushes I do all my non-destructive painting with a Raphael size 2. I can do large pieces like banners and the tip is sufficient for pupils and line work.
  
• Pink Soap It works and is convenient to use; I've been using the same bottle forever.
  
• Paint Brush Washer Cleaner I'm not sure if this is the exact one that I have and there's another on amazon with bad reviews but I love mine. It easily cleans all the paint off your bristles during your session and at the end you can hang your brush to dry tip down.
  
  And here's my three beginner pro tips:
  
  1 Always take the time at the end of your session to wipe the paint out of your palette. If you let paint build up in your palette over months of use then any paint you put in the palette will tend to dry out quicker.
  
  2 To clean your brush(es) at the end of your session put a little pink soap in an unused palette well, swipe the brushes through the soap, and then paint the palm of your hand to clean it. Repeat if necessary. Then paint your palm under running water to rinse the soap off the brush. Use paper towel plus the remaining pink soap in the palette well to clean the palette and then rinse it as well. Never let paint into the ferrule of your brush; clean it immediately with the brush cleaner/washer screen I linked above if this happens.
  
  3 Raise the miniature to eye level while painting. This is to save your posture and prevent you from hunching over or straining your neck. Most people try and hold the miniature in one hand right in front of their face but this makes detail work very difficult. I find it much easier to put my miniatures on something about as tall as my forearms (I use two Reaper paint carriers stacked on each other but a kids sand bucket would probably work too). Then I can rest my elbows on the desk and my minis on the "platform." I try to always keep the mini base in contact with the platform or, if I turn the mini on its side or upside down, then I hold it in my palm and rest my hand on the platform. Typically I rest the ridge of my brush hand on the platform as well and I almost never make a mistake with my brush because using a stable surface at eye level with my elbows and hands resting on stable surfaces keeps every thing still.