Definitions: One says that a map $\pi\colon\mathcal X\to X$ from an algebraic stack to an algebraic space is a good moduli space if $\pi$ is cohomologically affine and universal for maps to schemes. (A good (but not equivalent) way to think about a stack whose good moduli space is a single point is that for any two points, the closure of their orbits intersect.)
One says that a stack $\mathcal X$ is a quotient stack if it is the quotient of an algebraic space by a subgroup of GL_n (see for instance EHKV, which also gives a criterion for a stack to be a quotient stack in terms of vector bundles).
One says that a stack has the resolution property if every coherent sheaf is a quotient of some vector bundle; Totaro's paper The resolution property for schemes and stacks relates the property of being a quotient stack to the resolution property.
Question: Let $\mathcal X$ be a stack with a good moduli space $\mathcal X \to X$ such that X is a geometric point (i.e., X = Spec k, where k is a separably closed field). Suppose further that the stabilizers are affine linearly reductive groups. Is $\mathcal X$ a quotient stack?
(See this answer for the definition of stabilizer of a point of a stack that isn't a quotient stack.)
The condition on stabilizers excludes things like BE with E an elliptic curve.
The condition that k is separably closed excludes non-trivial gerbes.
I'd be just as happy with an answer to "Does the resolution property hold for $\mathcal X$ ?".