Mikey,
Clive has a post running about potential lighting to his buildings. Maybe there's some common ground here...(wow...what a pun eh
).
Nothing stopping you having overhead wires on poles. Very realistic and has many advantages.
You will need some hefty cable though even for short distances. Voltage drop can be pretty significant, about 2 volts over 60 feet with 1.5 mm cross section cable.
I would advise like Bruce and try and have a main trunk feeder cable of at least 4mm cross section and tee off of that with smaller cable, (that's what I have but it's buried).
Trouble is 4mm cross section cable will be difficult and too heavy to suspend from miniature poles.
Another idea is if you are not using track power for traction you could use the rails for electricity supply and tee off that for your buildings. You just need to be careful not to short out the track, a circuit breaker is a must.
A lot of people have done that.
BTW...The layout is progressing...looks good.