Alternative to a basin wrench?
Another wrench type for this situation is the socket type. I have seen some in plastic that may come with the faucet. socket basin wrench

Here is an ingenious tool video to use of plastic tube wrench and another video of same Rigid wrench 

I think I have seen simple ones that are little more than an 8 inch long tube with a slot along the length to slip over the supply hose. One end fits the nut holding the faucet and some other wrench is used on the bottom end. It is possible that you could have one fabricated locally out of steel pipe. The bottom end could be turned by pliers or a pipe wrench. The upper end could have wrenching flats soldered (or glued) inside the pipe.