JamesO, I am afraid that I just might have to build a yagi for 700mHz and put another antenna up some where else for VHF...
What you do not realize is with a proper LNA that has a low enough noise figure, signals can be pulled in with quite good results. So for example you are thinking you must have a 700 MHz Yagi when in fact you might be able to use a decent outside omni antenna with a high quality, very low noise figure LNA and be able to receive the system you cannot hear.
You can use regular RG6 CATV coax and put the money into the LNA, you could even use a very cheap antenna in many cases and still have good results.
The only down side of an LNA is if you have very strong signals in your area that would compress and/or cause intermods in the LNA. I had to use a FM Notch filter because I am 3-5 miles to 3 very high power FM broadcast towers, but after buying and trying 6 different FM notch filters and 6 different LNA's I found this combination works very well and I can now hear many of the adjacent systems that I could not have heard otherwise, even with the antenna I have set up now.
IMHO and experience people miss the big picture and focus on the wrong way to pull in signals. While the LNA configuration may not work in all installations and for all services, I have also had a lot of people claim this will not work under most conditions, which is not the situation in my case. I am 2 miles from Washington, DC and under 8 miles to almost all the FM and TV transmitters for my market and have a number of cell phone towers within 1 mile and I have very little, if any artifacts or problems due to the high level and quantity of signals.
This set up is something to consider, you might be surprised on how it performs but at the same time you may have some fine tuning or other things that challenge the ability to use this set up in your location. I am in a major Metro area that is an RF rich and RF challenging environment and I have very good results with this configuration. I hear things I would not have otherwise been able to monitor.