I could make it in a plugin so that when an admin joins sv_cheats will be on, but I dontt know about turning it off quite yet...
Also, I could give guns to admins when they join, but as for the 'make sure only admins can hold them', you would have to modify the script using something like this...
function onPickup( thepickerup )
if (_PlayerInfo( thepickerup, "networkid" ) == "Your Steam id here") or
if (_PlayerInfo( thepickerup, "networkid" ) == "Your Steam id here") or
if (_PlayerInfo( thepickerup, "networkid" ) == "Your Steam id here") or
if (_PlayerInfo( thepickerup, "networkid" ) == "Your Steam id here") or
if (_PlayerInfo( thepickerup, "networkid" ) == "Your Steam id here") then
_Msg("Authorized")
else
_PlayerKill( thepickerup )
end
end