the easy way to do it is;

put all ur seed together into a big tub. mix in a bit of peatmoss or sand or sumthing just to give it some volume. maybe a bit of water (not soaking but moist peatmoss) then throw in all the diff innoculants together into the tub and mix and mix and mix.

i wouldnt use a spreader for that small an area. i would mix the seed about 5 - 10 parts peat moss to 1 part seed and mix and mix and mix. then hand spread.
a spreader has a tendancy to first put out smaller seed and lastly leave fluffy seed. if u mix into sumthing, it makes ur seeding more even and easier.

seed right after mix with innoculants. sooner the better.

froggy