Unfortunately, as you have found, smaller pickups are not very child friendly.
With the airbag disabled, it is acceptable to have a rear-facing carseat in the front passenger side. This isn't ideal, but it is the best option for your vehicle. As for fit, your best bet is find seats that have the features you like, and make sure you have a good return policy just in case. You should also get a free carseat inspection (see http://www.seatcheck.org ) before you return a carseat. You can also try Toby's database if you haven't already ( http://www.carseatdata.org/selectseat.asp ).
It is not acceptable to have any carseat or booster installed in a side facing jumpseat. These seats really aren't safe for any passenger.