If you're willing to think more abstract and rely on the silhouette looking similar, then I went with the Aaliyah head and Lancel Core/Arms/Legs. I chose these for the general shape and effectiveness of the parts. The head is small and sleek with a single strip as the eye, the core has the general long and boxy shape, the arms convey a high-def version on acmoa's 9B minus the pointy shoulders but the height of the shoulders helps sell it to me, and the legs are the least believable part but the bulky shins with the thinner thighs makes it believable if you squint your eyes.
For the weapons, I chose the SPICA pulse gun (right); the 0700 laserblade (left); the OGATO grenade launcher (left back); and the three-cell VTF missiles (right back, forgot what they're called) with the BELTCREEK shoulder missiles.
The internals are the INBLUE fcs, the ARGYROS generator, the Aaliyah-M, Laytona-B, Oretga side boosters, and the KRB-Rigel overbooster.
The internals add a high degree of mobility and energy efficiency while maintaining extremely high capacity and output for both EN and KP. Tuning should always incorporate 50 points into EN output and however much in Capacity and KP output as desired.
Tuning is as needed, but EN output; turning ability; Main Boost; and EN Compatibility are primary for tuning. EN output and Compatibility should be max'd out. PA should focus on the core and legs for defense. Anything else is optional, but Arm Mobility is a decent option to support the INBLUE fcs and keep with fast-paced combat.
The colors are all black [0,0,0] with red [65,0,0] as a secondary color to represent the OG 9B. The eye is a deep electric blue [58,61,218] and looks amazing in the shadows. The stabilizers are red (primary) [65,14,9] and black (secondary) [12,8,5] to stand out a little and still look the part. The core stabilizer is all black though [0,0,0].
Stabilizers are Aaliyah-small for the legs-back, Alicia-large for both legs-front, and the SOLUH-large for the Core-upper-left.
Notes: not all the frame parts are the same colors in the same slots, but the core and head are mostly red with a little black, while the arms and legs are the opposite. Personally I find this machine to be quite OP, not as OP as certain broken builds but for a cosplay build it works extremely well. Hopefully you enjoy as much as I do, happy hunting Ravens!