I know Junior Gold 2019 is a long ways away, but i want to get as many suggestions as i can.
Edit: I throw 15 lbs around 16 mph and 550 rpms
I need help building a five ball arsenal for junior Gold 2019. I know im gonna have to bring my spare ball so that brings it down to 4.
my arsenal:
Plastic, OG Storm Hyroad, Hammer Purple Urethane, Hammer Black urethane, C300 Impulse Solid, C300 Eruption Pro Blue, Track 716c, Ebonite Mission Unknown, Hammer Gauntlet Fury, Ebonite GB2
I will also take suggestions on balls i could add in the next few months

Ebibowler you should include a short video of yourself bowling. Otherwise anyone here would assume your a great impressionist air guitarist. Or would you like to pet a hungry lion. Play fetch with the jackals. Better yet some Zombies.
Video goes a long ways to appeasing the autistic masses before giving feed back.

Bring a 500, 1000, 2000, and 3000 abralon. You can increase your "reactions" with 4 balls to realistically 12. Don't be afraid to "smoothen" out your look with whatever you take. It's a long tournament, getting the ball back to  the middle of the lane and covering spares gets you there. Smoother surfaces, more grit will minimize your splits and washouts. You want to be able to pace 200-205s every game with 1-2 miss spares bringing your score down to 180-190 instead of 140-150. Pop off a 230-240 each day and those +60,+50, +80 +30 days add up to +220, instead of having a day where you go +100 on your best pattern and -120 on a bad day.

Maybe attempt to learn to use the urethane for spares? Would open up another spot in your arsenal.

It’s the route my son has gone in case he qualifies this year.

If you're rev dominant Urethane could come into play, if you're speed dominant probably not as much.

Rev dominant:

Purple Urethane
Gb2
Impulse Solid
Guantlet fury

Speed dominant:

Guantlet fury
Impulse Solid
Gb2
HyRoad

Those are my thoughts. What do you use now on what shots?

I use urethane on short, urethane/hyroad/gb2 on medium and impulse and gauntlet on long