you could get the camaro but you would have to change it over to fuel injection in order to get OK gas mileage
the dodge dakota is OK but it would not get the gas mileage you would like
Keep the Dakota, older cars are more for show....I have a '79 Ford Econoline 150 with a 351W and a 4bbl, looks and sounds great, but gets about 10 gallons to the mile, LOL.
I love Camaros, I have owned five (1980 RS, 1984 Berlinetta, 85 Z-28, 96, and my current 1978).
If you are strictly focused on mpg, the 99 Dakota would probably be your best bet. If you want to have fun burning 8-14 mpg then get a Camaro tear up the roads!