A microstip transmission line is a printed circuit trace over a conducting plane with a dielectric between the trace and plane. A stripline would be a trace between two conducting planes with dielectric between the trace and the planes.
FR-4 is a specification for printed circuit board dielectric material. The designation stands for 'flame retardant class 4'. The material is fiberglass mat with epoxy resin. It can have a dielectric constant from about 3.4 to about 4.8, depending on the proportion of resin to glass and the specific epoxy resin used.
You need to specify the type of transmission line because it will determine the capacitance per unit length, the inductance per unit length, and the losses of the interconnects in your circuit.