coffeebaron: Try adjusting the antenna direction a little and see if it improves. You will definitely be able to get Freeview from where you are; it may just require a bit of re-tuning or bigger antenna.
I suggest adjust antenna until you get best available Prime, then get a Freeview decoder. If you then still have issues, then upgrade the antenna.
The reason his prime is crap is he needs to provide power to the UHF amplifier/combiner
You only need one, and generally you install it on the nearest outlet to the aerial.
You local aerial store should be able to hook you up with one.

