I can't do 80m. I don't have the room...
Gonna have a hard time getting the 66' or so for the 40m length..
Saving grace is tree is in back rear corner and maybe I can put up a pole on the front of the house which luckily is a 72' long mobile.
Consider a linear loaded di-pole, a 40 meter one in about 40 feet long overall,... an 80 meter one is about 66 feet long.
http://www.m0pzt.com/40m-linear-loaded-dipole/