One thing to note is that you don't need lateral thrust on a small ship as long as you put your fore and aft thrust out where it gives decent turning torque. It only really matters when you're trying to attack from a specific direction, which is really only useful against large, slow enemies. That'll save you 3k on these designs.
A second thing is that unless you're under space constraints (trying to squeeze a ship into 100% efficiency off a single jumpdrive or fitting behind a shield), smaller thrusters are cheaper per unit thrust. You might want to stick to paired medium thrusters for reverse because they're competing for space with guns, but for forward you could go to a bank of 10 small thrusters and save 3k while actually gaining 11% thrust.
Also, you can actually cut your forward thrust down to 4 safely now that you can set a ship's flight direction independently of thrust balancing. Using 2 mediums for reverse and 4 smalls for forward would save you another 2k. You might have to put in more forward thrust for professional zones to catch ion frigates, but if you're mounting missiles you don't have to catch them.
You can do quite a bit at this scale with an extra 8k.
