I am east of Toronto.   I have a Winegard 8800PR 8Bay on my roof.   I have a four port distribution amp, namely PCT-VB-4U.   I am getting all the channels in the expected portion of my local area.   There are maybe 2 or 3 three stations that I am not getting as they on the low end of strength, distance or 1 or 2 off LOS.   
My question is, putting money aside, what I can I do to grab those last 2 or 3 that I am not getting today?   Is there a better antenna or better amp to consider for example?