for performance and reliability youll use most of your money on decent motor and esc,dont bother with cheap piles of junk or it will cost you more in the long run
you'll want to run 6s at least and a 1400-1600 kv motor
lipos need to be at least 5000,30C constant rating
building is defo more fun,+ youll know everything inside out
you want to mount all the surface drive hardware 1st,turn fins,trim tabs etc before epoxying in the motor mount,batt trays etc
you want to start with around 28% CG with everything fitted but makeit so you can move your batts forward to increase the CG should you need to
Surface drive hardware go with HOR and 3/16 (4.79mm) flexi drive
youll need a decent MG Hi torque servo aswell
3 blade props work better on surface drive monos due to running smaller diameter