Normally stock shocks in a rtr buggy are light oils around 30wt. I honestly dont like any stock wt setups on any car/kit. Basically if its a basher or jumper go heavy wt and if its a racer it depends on track.
The t maxx should include enough oil to fill all shocks if not a bottle of fluid is like 4 bucks or less and will do 16 t maxx shocks if its ae oil.