i should use pre amp or just an distribution amp

i was thinking in install two converter boxes more to the two televisions that are not connected directly with the rooftop antenna and i do not know if need as will run 4 outlets an pre amplifier or an distribution amplifier, as my signal in certain Tv channels gets fluctuactions and some have lower ERP and other high ERP then i am not sire of what to get for compensate the loss by the cable run

any help would be appreciated

best regards
Francisco

A pre-amp will have a lower noise level than a distribution amp, and is therefore preferable.

Without a meter or signal strength simulation tool (like TVFool), it is hard to know if amplifying the signal will cause the strongest signal to be too strong in your case, but I doubt you would have any problems. Anything more than 20dB would be overkill.

You can always try just a splitter first, if you would like to see how it performs without any amplification.