The accu-cycle has a 2 amp output. It will take a long
time to charge the 4000 pack. Something like the
triton eq will be better. I have a triton eq so I know
about it. There are others just as good or better.
A power meter is a good purchase. Without one
you will never really know how many amps your
system is using. It could save you from burning
out motors and ESCs.
For your connectors, buy or at least choose your
charger, battery and ESC first. Then get whatever
connectors it takes to make it work.
A small lipo voltage checker is helpful at the flying
site.
Unless you are charging outdoors on a non flammable
surface far from anything valuable, a lipo charge bag
is HIGHLY recommended.
A fire extinguisher is also a good idea. You should
have a couple around the house anyway. You can
get a small spray can sized one and take it with you
when you are flying. It could save some components
if your plane catches on fire.
The ReadymadeRC website shows a 5000 battery
recommended for the penguin v2. They probably
have a reason for recommending that one.
Jenny