5-Axis BC Head Router – LinuxCNC Kinematics, TCP and Hardware

Hello everyone,
I’m working on an unfinished DIY 5-axis CNC router project with a BC head. The machine was originally built by a company but never fully completed, and it has been sitting unused for about 2 years. It never achieved proper simultaneous 5-axis operation.
The current setup is based on Mach3, without TCP/RTCP, so true 5-axis machining is not possible.
Machine configuration:
X, Y, Z + B, C axes
Stepper motors with encoders on all axes
Dual motors on the Y axis (gantry configuration)
BC head driven by stepper motors with gear reduction
Total: 6 motors
I’ve decided to rebuild the control system properly from the ground up using LinuxCNC.
At this stage, I’m trying to define the correct approach:
What is the recommended kinematics setup for a BC head machine?
How is TCP typically implemented in LinuxCNC for this configuration?
Are there example configurations I should study?
Hardware side:
What Mesa configuration would be appropriate for this setup (6 motors, dual Y, encoders)?
Is something like 7i95T sufficient, or would another combination be more suitable?
My goal is to build a stable and correct 5-axis system, based on a proven approach.
Any advice or pointers would be greatly appreciated.
Thanks!