You need a pre-amp for your setup, and the mast-mounted portion of the pre-amp needs to get its power via the same coax that's carrying the signal. The other half of the pre-amp is a power injector that goes inside the house.
If you install the splitter between the power injector and the pre-amp module, then you need to make sure you get a splitter that can pass DC power along one of its paths. That is, the DC power must be allowed to pass through the splitter along ONE of it's paths.
Most splitters are built to pass power along one of its ports, but some splitters pass power on ALL of its ports. You don't want to share power on ALL ports because that means the power intended to drive the amp might go elsewhere with potentially undesirable side effects.
If there's only a single line between the power injector and the amp, and you put the splitter "after" the power injector, then you have nothing to worry about.
In general, variations in splitter performance across brands is small compared to other things in your overall setup (e.g., antenna gain, cable loss, amp noise figure, etc.), so I wouldn't worry about choosing one brand over another.
It's more important to choose the right kind of splitter for the job. Depending on your setup, you may or may not need DC power passing. Split the signal only as many times as you need. You don't need an 8-way splitter if you're only driving 3 TVs. More splits means less signal power is reaching each end-point. Splitters are always done in powers of two (i.e., 2-, 4-, and 8-way), so if you end up with more ports than you need, you should "cap off" any unused ports with a terminator (like
this). Any ports that are left "open" can reflect signals back into the cable and can potentially cause a kind of self-interference. Terminators will prevent that from happening.