Suppose $a_1, a_2, a_3$ is a geometric sequence of positive integers with common ratio $r > 1$. Let $b_1, b_2, b_3$ be an arithmetic sequence. If $a_1 = b_1$, $a_2 = b_2 + 2$, and $a_3 = b_3 + 8$, and the common difference of the arithmetic sequence is a positive integer, which of the following are possible values for the first term $a_1$ and the common ratio $r$?