Future Challenges

My triathlon club is doing a "May Fitness Challenge" which consists of the following:

60 Miles Running
1000 Shoulder Presses
90 Minutes Plank
2000 Air Squats
1000 Inverted Rows
160 Miles Biking
2000 Wall Ball Sit Ups
10000 Stair Steps
1000 Push Ups
10000 Skips (Jump Rope)

I'm finding myself more motivated than ever- and I'll just barely get everything in.
I'd like to do something similar in June (not doing a triathlon this year)...
so far I'm thinking about substituting the following:

1) 2000 mountain climbers instead of the air squats
2) 1000 box jumps instead of the jump rope
3) 30,000 yards swimming instead of the running (which I hate right now)
4) 1000 back extensions instead of the inverted rows

Anyone else have any suggestions? Going out of the comfort zone has been the best part of this challenge, although I suck at jumping rope.