yes all are good
B3 - for small medium tracks $200
P5 - Best all round motor, great bottom and good top end $250
WS7II - Good Bottom end and explosive mid and top end $290
I use the Ws7 myself and it lasts well over 6 gallons!!!
once it loses compression get it piched for $15 and change the rod and it will last another 3 gallons!!