So here's my buying guide for the Soh Jin route. Assume that "+" means that number or more and "-" means that number or lower in order to get the rest of the items.
Good luck!
Tyrian Shield - Gencore Low Energy Shield Rear Gun - Sonic Wave 4 Notes: Kill the first U Ship as it paths diagonal for a rear weapon pod. Don't kill the rest in that U ship line to allow the secret orb ship to spawn right before the boss (you can kill a few of them and still get this, just don't kill them all).
Soh Jin Rear Gun - Sonic Wave 1 Sheild - MicroCorp HXS Class A Right Sidekick - Plasma Storm Front Gun - Pulse-Cannon 3+ Notes: Stay on the left side and use Plasma Storm for safety! Or don't if you're way better than I am, ya slick bastard.
Asteroid 2 Rear Gun - Sonic Wave 4 Notes: Wait for the starting tanks to turn around to get free weapon pods or specials
Savara Generator - Gencore Custom MR-12 Front Gun - Pulse-Cannon 4+ Notes: Kill Blimps for points!
Bonus (die) Generator - Standard MicroFusion
Mines Ship - - Gencore Phoenix
Deliani Front Gun - Pulse-Cannon 3- Rear Gun - Sonic Wave 5+ Notes: Free weapon pods from the row of three grey ships.
Savara V Front Gun - Pulse-Cannon 5+ Ship - - Gencore Maelstrom Notes: Kill more blimps. You should be able to to kill all of the easy, but use plasma if you have to.
Assassin Left Sidekick - Plasma Storm Front Gun - Pulse-Cannon 6+ Notes: Use plasma on the bosses arms, but save at least two to kill the body.
Torm (nothing) Notes: Kill the weird dragons for extra points. There's a weapon pod on the right side about 1/3 of the way through the level.
Gyges (nothing) Notes: Kill the Red Triangle Square with blue eyeballs enemy that appears early on for a free weapon pod.
Bonus (die) (nothing)
AstCity Front Gun - Pulse-Cannon 9+ Rear Gun - Sonic Wave 6+
Bonus (die) Ship - - MicroCorp Stalker
Soh Jin (nothing)
Botany B Generator - Advanced MicroFusion
Gryphon (nothing)
Gauntlet Rear Gun - Sonic Wave 7+ Notes: Free weapon pod on the left side.
Ixmucane (nothing)
Bonus (die) (nothing)
Stargate (nothing) Notes: Two of the spikes are killable. Free 20k if you get both, but considering how dangerous they can be, I wouldn't go out of your way to risk it. Kill the Tri-bubble enemies for lots of points.
Camanis Rear Gun - Sonic Wave 8+
Bonus (die) Front Gun - Laser 10+ Rear Gun - Sonic Wave 8 Notes: Laser reduces the load on your generator. Don't max to take advantage of the weapon pods in the next stage.
Fleet (nothing) Notes: Kill the unique ships that fire the small red blasts to get two weapon pods or specials
Surface Rear Gun - Sonic Wave 9+
** DONE. Add as needed if not max.**
