Spend your money once and spend it right.

My first antenna was a G5RV which is a poor antenna and is a non resonant antenna, that does work on 20 meters, but only 20 meters.

My second antenna was a Solorcon / Antron A99 Vertical - which works well for 10 / 12 / 15 and 17 - with my internal antenna tuner.
I do not like external antenna tuners.

Your technician class license will not allow you to operate anything lower then 10 meters phone 28.300 - 28.500 MHz USB....

If you are going to spend good money on a resonant HF antenna - that does not require a expensive antenna tuner - you would want to purchase a Barker & Williamson BWD 90 - folded dipole.

I'm not sure if you are going to be happy with your combo HF / VHF / UHF transceiver. It lacks good filtering and doesn't do anything especially well - other then it affords you the opportunity to use it in more then one band or mode...

The price of the B&W will probably be one third of what you spent on the 706..

For listening, it doesn't matter how high you put it up, as long as you put it up and use the best possible coax to feed it.

Two meters / 440 - you would want to purchase a Diamond X 500 and get it up as high as you can and feed it with the best possible coax such as the Belden 9913F7 or LMR 400