The junkers base is trafalgar. Look in 3C in New london system. Trafalgar sells legionnaire. Pretty good fighter.

If you are short of credits to bribe, which I am suspecting you are, I suggest the following trade route.

Get to New london and get yourself a Clydesdale. Load up diamonds from New london and make your run to leeds. Load up optronics from Leeds and go to cambridge. Load up diamonds again from cambridge and get back to leeds.

A few runs and I can get half a mil credits in like 20-30 mins.

That should give you enough to bribe your way into trafalgar.

If not, start blasting one of the house corporation ships. Since you are in the britonia segment of the game, I would suggest picking one of the rhineland corporations (republican transport and daumann are good options). Keep an eye on how it is effecting your reputation with other house corporations (especially IMG) and with the police/armed forces. After killing the nomads, you might want to run a few operations for the rhineland police to repair your rep with these these rhineland corporations.

Just an afterthought. You might want to get the crusader (aka fishmobile) from one of the britonia battleships (except the hood, Norfolk or suffolk are good options).

Remember you will need a ship with good maneuverability to get past dexter hovis in the race in dublin system. Both legionnaire and crusader are good options for that.

Cavalier (aka fishmobile without fins) and piranha (well it looks like a piranha) also have good maneuverability, but crusader has better weapon options which you will need to get quintane out of dublin into leeds and beyond till you can get into kusari space and buy a dragon or a barracuda.

Following are the turning speed of the fighters:
Cavalier - 68.75 deg/sec
Legionnaire - 68.75 deg/sec
Crusader - 60.09 deg/sec
Piranha - 68.75 deg/sec

Although crusader has less maneuverability than the legionnaire and cavalier, I get past dexter hovis quite easily using it. I prefer the crusader for the fights in bretonia segment of single player mode for its better weapons, but its your choice. I suggest you save the game before buying any of these, so that if you have to reconsider, you can come back and start over from the point of purchase.

Hope that helps.
Cheers!!