Fuel injection or aluminum heads

Ok this is my dilemma
I have a 73 duster with a stock 318 other than edelbrock 4 barrel and intake
I have a msd ignition system to install
Long tube headers and a mild purple cam
I have enough in my budget to buy a holley sniper system or mopar performance aluminum heads P5153849
What is my better option to buy now and save and buy the other at later date
I drive mostly on the street