I like option 2 better, but would opt for an
8 way amplified splitter instead of a pre-amp. Daisy chaining passive splitters after a preamp results in way too much signal loss downstream.
Why don't you just try this scenario with the ANT751 first since you already have it? If you find this set-up doesn't provide enough signal, you can move up to the C2V or 7694 antenna to improve UHF gain down the 50 foot cable run. VHF signal loss in 50 feet of RG-6 will not be a concern.