New diver, first build

As stated in my introduction thread, I've been diving for a while but always with a pole spear, I decided recently that I wanted to start spear slinging and being a hobby woodworker, building it comes natural to me.

So far, I have 3, 6 part laminated Honduran/Santos mahogany blanks glued up with WS epoxy, trued 4 sides square on the jointer, planer and table saw, and they have all been hanging for about a month. The moisture content on the wood was sub 8 % as it was kiln dried then has been sitting in my lumber rack for at least a year so I don't expect it to need to hang much longer and don't expect much warp or twist.

Two blanks will actually become guns, the third exists soley as a setup blank. I will use it setup the machines before making cuts on the actual blanks.

I'm currently planning on a neptonics reef mech ( honestly because I don't know about many other options), mid handle mounted, and an enclosed track ( gunna have to buy the ball mill since that's not a tool most woodworkers own.) as I have a bunch of purple heart on hand! I'm planning on inlaying about 18" of ppl heart into the end of the gun for support rather than derlin or uhmw plastic. The hardness and oil content should give me more strength than either of the plastics with the same low coefficient of friction. (I'd like to hear thoughts if I'm off base)

Currently, both blanks are 45". I will be hunting halibut, WSB, calico, sheepshead.. Pretty much everything that likes in the kelp beds between San Diego and the Channel Islands.

Some things I would like to get feedback on.
I have no idea how to choose a spear size.
I have no clue what power and number of bands I should plan for

Here are some pics so far including a handle of padeuk, Purple Heart that I tried shaping.

Pics didn't load

The glue ups took every 12" f style clamp I owned .

For some reason, it's only letting me attach one pic at a time.

How does one decide on a) band hole/slot location and b) weather to use two holes or an elongated slot? I'm thinking I will be using two bands and the two holes just looks cool.

I'm going rear set mech with a remote trigger about 11" in front of it.

Marco, I agree. The closest hole to the mech should be lower than the front hole allowing the front band to sort of ride up and over it. Sort of like an elevator?

Handle shaping is finally done. A lot of padeuk dust in the dust collector from this one.

Thank you very much for your detailed reply. I am still very in research mode but finding the paralysis by analysis taking hold. I have been in contact with Dan about what I am looking for and he gave some recommendations.
As far as what the gun will be primarily used for, I mostly hunt kelp lines where they transition to a sand bottom. Due to inner ear problems, I'm not a deep diver so 90% of my fish sightings are in open water/ hugging a kelp string or shooting a flatty layang on sand.
As far as the person preference, I both knew that answer was coming and dreaded it. I often have to give that a sweet to new woodworkers on my forum. Unfortunately, I don't have any data to compare to.
Knowing me, this gun won't be my last. As a woodworker, I'll be surprised if I use it for a year before saying "I'm building another one better".
I'm leaning toward a 7mm flapper shaft as I read a few places that is a decent "all around size. As far as length, the things I read were all over the place. I wish someone could say, "get 30 cm overhang and your good"

Another of those questions I'm sure has been hashed over a dozen times but I can't seem to find with the search function.
I purchased the reverse trigger mech from Dan's shop and have neptonics American shafts on their way. I can't figure out how a) the mono will attach to the spear as it doesn't look like there are any holes in the shaft and b) how the mono will properly fit back into the trigger mech and slide out with the shaft using an enclosed track.

Good to know. My buddy who is building along ordered the shafts so I didn't have much input there.

Next random question, is there a universally accepted depth to cut the enclosed track? I feel like the deeper the better for the strength of the upper side but too deep and the shark fins disappear. How much fin do most people leave exposed to the wishbone to attach to?

After thinking more about the build, I've decided that an enclosed track is not a good idea for me. With wanting this to be a jack of all trades gun for a while, I fear shooting into a rock hole and blowing the end of the gun out.
With that said, how deep do most people cut the open channel for a 9/32 shaft?

Thanks for the input guys. Parts should begin arriving tomorrow.
I understand that shallow track CAN be used, I just think I'll be more comfortable with burying the track down a bit.
Dan, I would have preferred enclosed but after watching a few YouTube videos of guys blowing their ends off shooting too close, I decided against it.
Next up will be setting the mech, pushrod& forward trigger.
After that, I'll cut the track, do some shaping of the blank with rasps, a cove bit, and roundover bit.

Once these are done, I'll tackle getting the power right. I'll admit it,that part I'm at a total loss of where to even start. Once I get the measurement of the bands slots to the fins, I'll post up some numbers and hopefully get some help.