how to pick an antenna

[emy]

hello,
i'm trying to purchase an antenna today (after researching for weeks), but i'm still unsure of which one to get.
for deland florida, which is 35 miles (north) from the station farm (?) i've been recommended a:
antennas direct 91XG Uni-directional hdtv antenna
it says i need pre amp and rotator
also a terk that is a smaller antenna
a weingard ss 3000 amplified (but it is for indoors)
and a winegard HD7698 HDTV hight band vhf-uhf antenna (its twice as much)
the tv person in my area uses weingard.
i don't know how to choose an amp or what a rotator is for that matter.
any help would be appreciated.
thanks, emy