my 2c
I agree with angus_grant: try Safale US-05 or Danstar BRY-97. Easy to use, suits the style & provides good results. Try rehydrating. Hotly debated in it's necessity, but it's pretty easy to do & possibly improves the result. Also, it just gives you a little experience playing with yeast, esp for later culturing efforts on future brews.
I'd look at doing something similar to mosto, or yum beer/pfs:
1 tin Coopers APA
1kg BE2/LDME/ADME
[150g Carapils or Crystal; not necessary, but i think it'll help a lot & round out the beer. It's pretty simple to do]
20g Galaxy @ 10 min
20g Galaxy dry hopped
US-05 or BRY-97 yeast
Steep the Carapils/Crystal in a pot with 1L water at ~60-70°C for 30min (longer is better). Stir regularly. Strain the liquid. Discard the grain.
Add another 2L to this liquid & bring it to boil.
Chuck some BE2 or DME (i like malt, so i'd go DME, & maybe even make it an Amber one). I'd go 1kg all in.
The idea is generally to get the wort in the pot to SG=1040 to optimise extraction of the hops. However, i'd suggest this normally refers to the bittering acids. For this method you don't want those so much. Instead you want the oils to come out & bind into the liquid. This should be faciltated by having a higher SG. (Hopefully a more experienced brewer can correct this if i'm full of sh#&)
Once back to a rolling boil, throw in 20g Galaxy.
Boil for 10min.
Chill pot rapidly to drop the heat - get it down below 50-60°C preferably. Use a water/ice bath & sit the pot (with lid) in it.
This is to stop the hops producing more bitterness [get it below 80°C] and then to reduce the volitility of the hops oils [get it below ~60°C]).
Put this liquid, plus the tin into the fermenter. Bring it to full volume at 22-24°C
Rehydrate your yeast (lots of simple instructions how to do that) & pitch.
Dry hop 20g Galaxy when you're 3/4's or 4/5ths through the fermentation.
Generally said to do it at day 4. I personally find more like day 6-7 is better. Still a tiny bit of activity to disperse the hops contents, but not much CO2 production that will scrub out the Galaxy aroma.
For a 23L batch,
IBU ~23.5
OG = 1040
FG = 1010
ABV = 4.4%
21L will be more concentrated, so all numbers go up a bit. Generally i'd prefer that - better body to the beer. But your bitterness will be close to 30 IBU. Might be a touch strong if you don't like a little bite in your bitterness. (i find i notice a step up from ~25 ibu to ~30 ibu, but that might be just me).
I'm guessing you already know most of the detail i wrote; but i started not that long ago & i still remember reading recipes, following most of it, but then having to waste many minutes working out a few simple step in them.
Hope that helps. Galaxy rocks! :super: