Systems, kits and methods for long bone arthroplasty that include arrays of humeral head prosthesis components, each having on a first side a bone articulation surface that has an overall generally hemielliptical convex shape defined by a major axis and a minor axis, the bone articulation surface having an apex and a base that each has an non-circular elliptical cross sectional shape, the prosthesis components having on an opposite side, adjacent the base, a bone contact surface. The humeral head prosthesis components in the arrays vary from having a base with a more circular cross sectional shape to a more elongated elliptical cross sectional shape with increasing size.