garage lighting question

Besides the light dispersion issues mentioned by others just installing 3 of those will draw 10 amps. Don't know what you have for electrical service in your shop but that is 1/2 the capacity of a typical 20 amp circuit.

You can get 4' fluorescent fixtures for about $10 each at Loews or Home Depot. T-10 bulbs for them are 14 watts each. A much more economical way to go.