DEI - what’s the differences in paging?

You asked if it liked that for all alarm system no it depends also but usually it some 2 way pager.

if all you need is paging, dei makes an add on pager piece... it's a real pager system that gives a better range. can't remember the part# but i'll check at work tomorrow.

and what i meant was that if the clifford only worked with the one lcd remote, there is a good chance that the others you listed did as well... being that they are all made by dei.