Usually I prefer lists that have 4 TIE Bombers all build the same, but I decided to mix it up a bit. I love Omega Leader, so he is a pretty easy inclusion for me. With 25 point Bombers that leaves me two options: Downgrade or replace one. Downgrading is boring, so what fits into an imperial 24 point hole? Right, Doomshuttle. Which leads to:

Scimitar Squadron Pilot [25] * 2

• Homing Missile [5]
• Seismic Charges [2]
• Extra Munitions [2]
• LRS/Guidance Chips [0] according to taste, testing, and availiability.

Omega Leader [26]

• Juke [2]
• Comms Relay [3]

Omicron Group Pilot [24]

• Darth Vader [3]

http://geordanr.github.io/xwing/?f=Galactic%20Empire&d=v4!s!49:126,-1,17,-1,24:-1:24:;49:126,-1,17,-1,24:-1:24:;187:152,153:-1:-1:;56:-1,-1,45,-1:-1:-1:&sn=Unnamed%20Squadron

Everyone fires before the Doomshuttle, so the crit is highly likely to happen on shielded targets. The list also makes target priority difficult for the opponent: The Doomshuttle should be focused first, which means it is very likely that the Bombers can deliver all of their payload. Additionaly you really don't want to face OL late game. The list has good anti ace tools and a tiny bit of regen. One thing I would consider is dropping the charges and upgrading the Bombers to Gammas, since in my opinion Bombs on low PS ships lose value when there are less, but I don't think too much would be gained, since two Homing Missiles probably won't kill a Y-Wing before it gets to shoot.