Avenger would be a bright, since it's experimental and never went into extended production, which the Defenders apparently did, since they showed up in several novels instead of just the game.
Viability of four TIE Bombers at 100 points
Should try 5 Scims with Prots or Concussion instead. If 1 dies, still have 4 missiles. The goal is NOT to get tyecrange 3 shot, but plan for Range 2, as you will probably be able to TL. Also, without Jonus, there's no reason to group up tightly, so you can come in at a variety of angles, making it harder for your opponent to rush range 1. I think 4 scims like you have built could work if you fly them this way. Just don't line up head on, make it tough on your opponent. don't count on clusters to be reliable without jonus, or even with. The 2 separate attacks and 2 evades means average damage is sometimes lower than concussions. I like just using primaries at range 1.
Tie Avengers are actually called Tie Advanced. They were called Tie Advanced in the X-wing/Tie Fighter game. The name Tie Avenger was given to them to distinguish them from Vader's prototype fighter.
The Tie Avenger/Tie Advanced has always taken a back seat to the Tie Defender since they kinda both do the same thing except the Defender does it better.
As for Tie Bombers...They are tricky as they require practice to be good and you have to build them right. I have experimented with a lot of Bomber configs. The one I've had the most success with is:
Jonus w/ptl & assault
2x Gamma w/ clusters
1x Gamma w/clusters&proton torps
Gammas are worth their weight in gold, you gain a large power increase by moving after your target. I've had more success with an offensive Jonus over supportive Jonus, I really like the ability to fire 4 projectiles in a single turn - it is really deadly. Supportive Jonus definitely has benefits tho - its much more flexible. And you have to be really careful when giving a bomber more than 1 projectile - the one bomber I have in my list is in the back and has 2 more for flexibility.
The biggest downsides to bombers are after the missiles are gone they take a long time to kill things - but can often win the attrition battle in the long run. And they are weak to squads that move after they do - esspecially if they have boost or Expert Handling.