I don't know if this has been resolved for you, but, after some tense moments, we ended up using an double-ended "offset" screwdriver we happened to have around. It looks something like one of these:
There are also a variety of "Offset Ratchet Screwdrivers" online, like this one:
For your second question, you need to pre-drill into the studs with a corded drill (or cordless) with at least an 1/8" drill bit, and for screws you can get some No. 10, 2" pan head phillips screws (usually used for sheet metal).
I'm sorry I don't know what is available, or the terminology in the
, or the conversion for inches vs. centimeters, but Google is great for that! (Or your local hardware store.)
I couldn't bear to think of you left stuck with this. Hope this helps!