PM sent; check your inbox. I've for a clearance sale on New in Box Fedeeal Signal & Whelen dash/deck lights.
My first recommendation for the most basic utility setup is: a lightbar, HLF, & intersection surface mounts. Unless it's an unmarked PD vehicle, I don't think there's a reason why you shouldn't go with a lightbar (it's cheaper to get solid 360 warning with a lightbar than multiple interior & perimeter lights). A used MX7000, vector/vision, or edge lightbar with new lenses could do a solid job for under $500.
However, if you decide to stay with a slick top vehicle:
--HLF up front (since you've got a really limited budget, keep it simple and don't worry about HAWs up front)
--TLF (economical option) or 2 HAWs in the rear upper brake lights. Do yourself a favor and don't even think about putting anything in the reverse lights (aside from many people being opposed to clear in the rear, LAWs are useless there because the housing & reflector are so small, and strobe HAWs give off too much heat for such a small housing)
--Dash light (centered)
--2 single dash lights on opposite ends of the rear headliner (preferably), or 1 dual light centered
--If I'd put the grill lights on hold for now and use your limited current budget toward surface mount lights that you can use for intersection warning. I'd say intersection is a priority here over grill lights (since it's a dept vehicle and I'm guessing it will be capable of going code 3). Then, once some more funds trickle in, I would get the largest grill lights you can get your hands on (I hate when people put TIR3's in pickup or SUV grills, because they look so tiny IMO). A pair of Lin6, M6, etc would look great.