SatMex 5 (C band) in Nicaragua

Not necessarily. SatMex 5 is an older satellite, with less power than the new neighboring SatMex 6 at 113 West. From my northern location (SW Wisconsin), SatMex 5 does have fluctuations in signal, and great differences in power levels between transponders at times. Strong signals on SatMex 6 may actually negatively affect reception of nearby frequencies on SatMex 5, so smaller antennas are not advised.

Would suggest that you check locally and see what people are using successfully and get comparative quality readings on various frequencies.
I would start with a 6 foot prime focus model or larger, for best results.