Hi there,

Not sure what exactly you mean by not having to "worry about going through security....." Once you go through immigration and are no longer airside, you have little choice but to go through security again!

With that length of layover, my view is that you can consider ANY hotel that is reasonably close to the airport (say around 20 mins or 30 mins max) - of which there is a fairly wide choice, depending on personal budget of course. There is plenty of time to have an evening meal, whether at your chosen hotel or perhaps in a particular part of Dubai that you might wish to see. Then a good night's rest before setting off at 7am to allow a 7.30 check-in for the onward flight.

HTH

Edit : my post crossed with response by m3red, who knows his way around DXB far better than I do ; but looks like we're pretty much on the same wavelength anyway.
.....and yet another edit ! I meant to say 8am from hotel for an 8.30 check-in....so plenty of time for brekkie at your hotel too ....