Druids

Okay Tut, here's Druid spells and advancement through 6th level. It's pretty fierce, really.

LVL.....1st.....2nd.....3rd.....4th
1: .........2
2: ........2..........1
3: ........3..........2.........1
4: ........4..........2.........2
5: ........4..........3.........2
6: ........4..........3.........2.........1

Yup, circles first through third at the same level. It's fast.

Here are some good spells.

1st: Animal Friendship, Ceremony, Detect Balance, Detect Magic, Detect Poison, Detect Snares, Entangle, Faerie Fire, Invis to Animals, Locate Animals, Pass w/out Trace, Precipitation, Predict Weather, Shillelagh, Speak w/ Animals

2nd: Barkskin, Charm Person/Mammal, Create Water, Cure Lt Wnds, Feign Death, Fire Trap, Flame Blade, Goodberry, Heat Metal Locate Plants, Produce Flame, Reflecting Pool, Slow Poison, Trip, Warp Wood

3rd: Call Lightning, Cure Disease, Hold Animal, Know Alignment, Neutralize Poison, Plant Growth, Protect. from Fire, Pyrotechnics, Snare, Spike Growth, Stone Shape, Summon Insects, Water Breathing

4th: Animal Summon I, Call Woodland Beings, Control Temp, Cure Serious Wnds, Dispel Magic, Hold Plant, Plant Door, Produce Fire, Prot. Lightning, Repel Insects, Speak w/ Plants
...

There's really no reason not to stay 1st level Bushi and dual-class into Druid. You've got the stats.