Which spark plugs, and where/how to go about doing a trans flush

OK, well like i said which spark plugs should i put into my truck. It has about 86K only had it about a mo. and the previous owner has no idea what he has serviced so im going through everything and all i have left is the coolant, trans, and plugs.

1. Which plugs should i get? i.e. dealer, NGK...?

2. How should i do the trans flush, drain and fill with the ~3 quarts, get it flushed with a machine, or do the one where you remove the trans hose and run it, fill, it run it..etc?? or do the three quart pan drain and fill, drive it a lil, re do that pan etc. a few times?

3. When i do the coolant flush, which coolant should i use?

 

No help?

 

For the plugs I recommend using the Toyota Denso plugs.

For the coolant use the pink toyota.

I haven't done my trans yet so im not sure about that.