Which is the most easy to keep spearer mantis and how I can keep it?

[Picasso the Triggerfish]

I know that boxer mantis are easier to keep than spearers, but I absolutely love these guys and im planning a 120L (~32G) species only tank with a tick sand bed (due to they love to burrow and wait) Which is the best species for begginers talking about spearers? What are their requirements? What do I need to feed them and how often?

 

[Picasso the Triggerfish]

I know that boxer mantis are easier to keep than spearers, but I absolutely love these guys and im planning a 120L (~32G) species only tank with a thick sand bed (due to they love to burrow and wait) Which is the best species for begginers talking about spearers? What are their requirements? What do I need to feed them and how often?

I also forget how thick the sand bed needs to be

 

[Picasso the Triggerfish]

I decided that I will buy a P. Ciliata with a 15 cm (~6") thick sand bed (since they are 10 cm (~4") long) and will be feeded with gut-loaded ghost shrimp and freshwater feeder fish (such as goldfish) 2 or 3 times per week and the tank will be 80L or 91L (~21 or ~24) blau AIO, what do you think?

 

[Picasso the Triggerfish]

As another update, the tank will have a U-shaped PVC pipe as a cave with a normal sand bed ore some rubbles as I discovered PVC pipes work with this species and it will have a Caulerpa algae and will also have some hermit crabs and some 4 stripped damsels to keep it entertained or to help me to keep it