Hi There
If i was closer to you i would take it on.
What type on finish are you going for smooth to be painted ?
If your backing is brick and has not been painted etc a good power wash to clean it seal it and mesh over any suspect areas.
You would be looking at a 3-1 scratch coat for the entire building this would have to then cure for at least a week before the second or final coat is applied.
4-1 or poss 5-1 for you final coat, would need to be feathered up with a straight edge, then use a float to get your final finish. I like to go over that again with a sponge to get a not to rough but decent finsih with a bit of a key for painting at a later date.
Also waterproofer would need to be added and plasterciser.
Weather wise is a hard one, really a cloudy day no rain etc, wind can also be a problem and can dry what you have done too so it will blow off the wall.
I would also consider setting in angle beads around the windows and doors etc so you get a nice tidy sharp corner. You can use batttons but it is far easier in the future to chip and damage corners without a bead set in.
I hope this helps you out, not sure of the price in your area but i would imagine it is going to be around the 20-25 pr sq mtr there, down in sunny wales its about 14sq mtr.
I have also been made redundant in the last seven days and plaster part time so this would have been ideal for me but the distance is the problem as i have a 3yr old to look after.
let me know if you need any more help
Paul