Ok, got it! I'm going to run this (please forgive the formatting, typing this on a mobile)

Krassis with HLC,

Bounty-hunter with engine upgrade and gunner

Dark curse

This way I get to try a few things. Firstly, krassis with an hlc. This always seemed powerful on paper, but the jury is truly out on how useful a hlc is on a firespray. I can imagine it requires some deft flying to keep it at the right range, but I'll try to keep K-Trel back of the field and see how this works out.

For the other BH, he's kitted out with the equipment I think will make him as reliable and easy-to-use as possible, 'cos I've never flown these things before!

Then finally, if I'm gonna be imperial, I better get used to flying ties, and having a cheap, named pilot seems like a fun idea!

If you can afford only a single cheap fighter to flesh out your list, there is no better option than Dark Curse. Any other TIE would have a huge target painted on its head, but the difficulty posed in actually hitting Curse will give your opponent second thoughts. By fielding him alongside two Firesprays, you effectively present your opponent with no good options.

The best escort for two firesprays is a third firespray!

A Rebel Captive.

I ran this list and won a store championship.

Bounty Hunter - Gunner

Bounty Hunter - Gunner

Saber Sqn - PtL

The Interceptor really carried me as my opponents tried to focus on my Bounty Hunters early on. Late game the Interceptor just played dodge with the remaining low PS pilots and finished them off. That being said, having had more experience with using two Academy TIE pilots as blockers, that would probably be a stronger option once you've gotten used to using them as blockers and harassers.