As for my current splitter, I don't know if it's high quality or not. It was provided by a cable guy a while back when he said my cheap Walmart-bought splitter was crap. So I guess I can assume it's alright.
Unless your signal strengths are borderline there shouldn't be too much practical difference between a store-bought splitter and the better stuff.
However, for piece of mind, the brands the cable companies use (which are the better stuff; it makes financial sense for them to pay a few pennies extra per splitter, since even one truck roll to your house for one of their splitters failing could pay for tons of splitters) are easily available cheaply on E-bay or the speciality stores (SolidSignal, SummitSource). Antronix, PCT/ChannelMaster, Regal are examples of the higher-grade stuff.
You don't need a splitter that goes all the way up to 2400 MHz for cable (but you would for sat.)
Figure how many splits you need and buy a splitter with exactly that many. An unused port still is weakening your signal by its very existence (for example, a four-way splitter is still splitting the signal equally in four, even if you only have three connections hooked up to it)
For distribution amps, I'd avoid the Radio Shack-type or Home Improvement store amps - their Noise Factors are outrageously high (like 8). I think Amazon (and some Best Buys) sell the Motorola ones (2.2 NF off the top of my head). SolidSignal and SummitSource carry the PCT/ChannelMaster ones (which are 3 or under, IIRC).
You can find amps with a single input and a single output (cheaper, but less convenient - to split, you would need to attach a short piece of coax cable to a splitter), and with multiple outputs (which are amps with built-in splitters - you can find 2 port amps, 4 port amps, 8 port...)