You should have latched onto the first run of Cordobas @ $499.
The NovaRossi 221's or 721's are decent for the buck for club racing.
RB has some good club engines- S7C, C6 or Xenon (ABC version). The C6 (Nova based) is a good engine for the money as is the Xenon (Sirio based)- like $400.
You can also get a 321P or a R1WC01 for around $400 at Brooklyn Hobbies.
on a budget I'd go 321P, C6 then Xenon in that order- excellent value engines around $400!!
If the sky is the limit- 359, Cordoba, 35+21- $500 and up.
Steer clear of the Ninja and OS for onroad.
FUTABA 3PKS/KO PROPO
BYRON'S FUEL/TWISTER TIRES