25 feet is plenty high enough for the apex. If a dipole is less than 1/4 wave off the ground they work the best for NVIS, it makes the radiation pattern more omnidirectional, and they work pretty respectable on long-hop. I talk to a guy in Texas all the time that has his dipole stapled to the top of a cedar fence - on less than 100 watts of power.
Basically, you can ignore all these people that claim you have to have your antenna 70 feet in the air. You don't. You're bouncing off the F2 layer at night and that layer don't care how high your antenna is. The closer to the horizon you can bounce off it, the longer the skip hop will be. But then do you know what your going to get? Some dude in Louisiana that talks in a southern drawl with a roger beep power mic and is impossible to understand. All the locals out to 500-600 miles you'll be skipping right over the top like your vertical does now. You have to have the antenna down on the ground so the radiation takeoff angle is really steep and goes just about straight up if you want to have fun on your local nets.
Full wave sky loops also work really good, but it requires four supports, one at each corner of your lot, to hold the loop up to a decent height where you don't get tangled up in it doing normal things around your lot. It can be fed at any place in the loop.
A dipole also does not have to have the legs or elements straight. They can be bent in a "L" shape if you want, and it still works fine. Especially an inverted V dipole, because the maximum current is at the center (the apex) and that is also the point of maximum radiation, while the maximum voltage is at the ends. So you can come off the roof peak, for instance, run 33 feet in one direction, attach to a fence insulator, and run the next 33 feet in a different direction, parallel with your lot line or something and terminate it on a wood post. When you put bends in the elements of a dipole, it works best to have the lengths between the bends 1/4 wave length. Same with a full-wave sky loop - each "leg" should be 1/4 wave length at the highest freq you want to use the antenna on.
When you get your tower up another really neat antenna you could build for really cheap, and that doesn't need to be more than 8 feet off the ground is a delta loop. One of the guys on our farmer's net has one and you can change it from horizontal to vertical polarization by changing the feedpoint.
There's always a way, that's why they call it "ham engineering". And none of these wire antennas cost more than about $25 bucks. Tomorrow I predict you'll wake up realizing you had a "vision" as to how you can put up a 80 meter resonant dipole with what you already have, and it will be so simple you'll slap your forehead and say, "why didn't I see this before?"
