Regardless of which extension tube is used, the AIS 55 f2.8 micro works best when focused all the way to the close focus position. In this way the optics are best configured for closeup photography. So, if you want 1:1 magnification, the PK-13 tube with 27.5mm extension is the best option. If you require slightly less magnification in the range between 1:2 and 1:1 then one of the shorter tubes is better, such as the PK-11 (8mm) or PK-12 (14mm).
On the other hand, if you need magnification just beyond 1:2 and use the PK-13 extension tube, the lens will need to be "focused" near infinity. In this setup the optics are configured for near-infinity shooting so performance will be less good (probably field curvature etc). In this situation it is better to use a shorter tube and focus the lens all the way out.