High Powered Wireless Network for Audio

I have frustratingly low signal strength and erratic performance with the wireless network in my house.

The culprit may be a combination of 1) ordinary Verizon DSL service and 2)a wireless G router? and/or 3) brick chimneys and concrete block within the walls of the house?

To hopefully improve, I am switching to a faster cablem modem service from Cablevision which I will install by my desk for at least a robust connection there.

Could anyone please recommend a wireless router for maximum range and signal strength? Has anyone used any wireless boosting devices? In Stereophile, I have just noticed Gigabit Powerline HD - could this be a better solution?

What is the best way to ensure a robust connection and trouble free streaming on multiple devices?