Gradient Descent or Normal Equation?

If you can, it is preferable to use the normal equation to estimate the coefficients for multivariate linear regression. Since the normal equation is a closed-form expression, it will be faster than gradient descent.

Given you have relatively few examples and features, inverting the matrix is not an issue.

You need to think in terms of sample size.
You don't have enough examples to use Gradient Descent. I believe you need at least several 100s.
Conversely, doing inverse and transpose on small matrices like this with Normal Equation should be pretty fast.