JC's recommendation of the HD7082P is a premium solution, not overkill, but appropriate if you want to see the lower powered stations, particularly those using 'real' low-VHF channel assignments.
If you have a gable style roof, you can avoid the use of a tripod by choosing a
Wall Mount. I am reluctant to put holes in my roof too. If a tripod is the best option for you, be sure to use a
Pitch Pad Kit and appropriate amounts of roofing cement. Depending on your roof type, you may want to ask someone in the roofing business.
You have quite a lot of signal to work with, so much in fact, that many amplifiers would be expected to overload. The distant, weak signals would require extreme measures such as much larger antennas and possibly a high tower... and then you would still be facing problems of co-channel and adjacent channel interference. If you have an interest in DX reception, I would think you would want to consider a separate antenna system for local vs. DX.