What is your lug pattern and stock tire size?
Mazda Miata and MX3 stock wheels can be found for cheap and are decently light. My MX3's are ~12.5 pounds a piece. They are 14x5.5".
If you want the best mpg tire... Bridgestone Potenza RE92 165/65R14 @ 50-55 psi
I'm running a cheap Chinese tire that is 1" bigger than stock, 24.3" vs. 23.4" I have done very well with them, even with the tires being non-LRR and bigger than stock.