Sorry, didn't mean to confuse you with too much information.
Either the 3410 or 3412 amp will work for you if you split down below, and you can split in either place. There is no advantage to splitting near the antenna after the amp, except for the convenience of coax runs.
The closer the amp is to the antenna the better the results, because the coax loss between the antenna and the amp input subtracts from the antenna gain.
Using a preamp with an indoor antenna can receive signals that are about 5 dB weaker than without a preamp, and the signals are made stronger for distribution, which is the part you need.