- There are plenty of VHF/UHF repeaters in the Sierra Nevada that both of you should be able to access. A Technician license will do the job. They often sit unused.
- I had to lookup Oakdale. Plotting out 150 miles puts him south of Visalia and definitely south of Fresno. Still, if some omnidirectional antennas do not do it, vertically polarized Yagi's will get you both to one or more repeaters. Knowing the city his is in will help me figure out things a little better. I am also here in the valley near Fresno. If you both wish to talk with others as well as each other, this is probably the way to go. A 20 foot tall mast and a dual band mobile radio in your house and or vehicle will work. There is also cost for antenna and coaxial cable.
- HF is plenty of fun when you have your General license. As previously noted, 40 and 80 meters would be the best chance. You could each setup a NVIS antenna configuration. 100 watt radios would be fine.
- Another option would be to setup a hotspot at each of your locations. Basically, the devices are a go between with your radios that send your communication over the Internet. Each of you would need one. They can range from $100 to $200 for a SharkRF openspot. Basically, the money you would spend on coaxial cable, a mast and antenna would instead be spent on the hotspots. You could use a handheld around your home property and talk with each other. You still need to follow the 10 minute rule on giving your callsign. While this method is not totally private, you should at least have little to no interference.
Much depends on what you both want to do. Tell us more and you will find many are happy to help. You will also find people providing advice that is not quite prudent for your needs. You both should consider how you plan to use the equipment. Each of your needs may differ, which is fine.