F103 or F104W better 啦..... wider, more stable, therefore can go much faster "confidently" ....
Best and cost effective way to get 104W is to buy 104Pro black (with light body and alu motor mount etc), then change front arm to 103 and use 103 tyres front and back.
I just joined the 104 family!
savox 1251 or futaba mini servo?
Any low profile sevo (short) servo is good. If use low profile servo, it can be mounted horizontally (servo saver on the top side instead of in front) so no need to cu ears. Savox is a good choice.