I'm the owner of a server, currently around 50 players, and would like to enlist in some help of admins.

I wondered if there were any plugins I could utilize, that would allow me to restrict my admins so they could not use the F1 menu to spawn items.

Give plugin, Limited Admin, etc. You could also not give them owner/moderator and instead use plugins with permissions.

I see, after posting this, the plugin with permissions was my immediate thought, but I figured I'd leaveit up just in case. I had seen the Limited Admin, but all I seen in there was to limit them from doing normal player things.

Thank you for the reponse

If you dont even trust your admins to not spawn in stuff i doubt you can trust them with anything else. But ontopic: I would use adminlogger and make a private channel with a webhook so you can see all actions by admin (including giving of items)

I had plugin that only allow autorized admins from the config and used to block give command form game and console so you cant abuse and spawn shit but I am sure its broken idk. I can give you the plugin on DM. Its called ZLevelsRemastered because used to make it hidden through other plugins in case someone try to disable it when had same problem with one player that used to help me as admin 2 months and I did this on time before he even attempt to spawn shit
Also you can try one of the plugins Wulf suggested you above they are good too.

Flammable

I had plugin that only allow autorized admins from the config and used to block give command form game and console so you cant abuse and spawn shit but I am sure its broken idk. I can give you the plugin on DM. Its called ZLevelsRemastered because used to make it hidden through other plugins in case someone try to disable it when had same problem with one player that used to help me as admin 2 months and I did this on time before he even attempt to spawn shit
Also you can try one of the plugins Wulf suggested you above they are good too.

As far as i can tell from using Zlevels remastered (for many years) it only "levels up skills and increases gather/craft/aquire rate, you cannot use it to *spawn anything (?) You have a gui onscreen that tells you your skill level.

This was simple custom written plugin to be undercover like its ZlevelsRemastered incase someone with FTP access try to stop it remove it wont suspect its called like this and was doing kicks for non autorized admins and blacklisting give commands. Its not the actuall Zlevels you talking about with the levels and stuff :D