I doubt either of those options will make any difference. You definitely don't want a CM-7777 with 30 dB gain. That's way too much in your situation. The AP8700 is a better choice if you want to try a preamp. You cannot stack two HD7698P antennas because the stacking distance is radically different for VHF and UHF. You need separate VHF and UHF antennas and stack them like you see in my avatar.
A preamp will give you perhaps 6 dB more signal to noise and stacking antennas about 2.5 dB.
Since I don't know what your receive margin was originally and I don't know how far below the cliff the signals were last night, I can't say how much more signal you needed. This assumes that multipath did not become an issue. My experience is though that once you have a decent outdoor antenna, it's very hard to make much more progress. The antenna you have is probably giving you 80% of what's possible even if you went extremes like I have.
An AP8700 is probably the most bang for the buck. It might push 80% up to 85%.
42.1 ... 6 bars and is located at 135 degrees
The rest are all at 1 bar out of 6 some of which are in the 51-54 degrees. I think these were 3-4 bars before yesterday.
This is with only one tv hooked up that has a twin tuner. I would like to have 4 tuners.
Do I also need a amp for multiple tvs?