The first thing I need to mention is your choice of Class 'C' for the PA. Class 'C' amplification is non-linear therefore unsuitable for AM. Your modulated signal would probably be completely uninteligible. For AM RF amplification, you are restricted to Class 'A', or 'AB' for best performance. Class 'B' could be used; however, crossover distortion is difficult to prevent.
Class 'A' would be the easiest to implement, but the least efficient. It could be built single ended with a relatively simple circuit.
Class 'AB' requires a push-pull output stage. It would be more efficient than the Class 'A', but more complicated.
To comment on the antenna, you need to tell us what center frequency you are planning to transmit/receive. You also meed to tell us what space restrictions you have - i.e. is this to be handheld, base mounted, etc.