How many TVs are connected? Depending on your signal strength and number of tvs, splitting with a dedicated splitter box is possible. However, each time you split, you’re sharing the signal between TVs. There comes a point where you split too many times and the signal is too weak to each tv and you loose channels and get pixelated. What this magic number is and how strong your signal is without test gear is a guess.
i have found distribution amps are much of a muchness. Nothing really special about them. I’d just get one with the appropriate number of outlets from somewhere like
screwfix where you can easily take back if you’re careful with the packaging.
If you’ve got a good input signal I’d be surprised if a new amp isn’t simply a case of plug and play.