Get SB-700, better and you no need to upgrade better flash when you going for FX.
55-200mm may suit your needs now.
Flash I don't really go for 2nd hand as some people may abuse it(continuously flash it during event), maybe knowing the capacitor and bulb's price will be good(this is the parts that may fail). If it is just rm100-200 cheaper than new, then just go for new.

Yup, fully agree 

Only 2nd stuffs that I'll consider is D lens, since it has minimum electronic parts inside.
Others I only consider if they price are <50% from its current market price.

Bro, where do u usually get yr stuffs?