Wanted : 12V UBEC for FPV Setup. ( Power to Vtx and Camera )

you can make it yourselves with a single 7812 3Pin voltage regulator.

Will this be good enough to power 12v vtx and fpv camera..?
www.reuk.co.uk/OtherImages/lm7812-12v-linear-voltage-regulator.jpg

Will use separate 3s 2200mah lipo to drive it.

yeah, that's the circuit I said with 7812, But you can't use 3S Li Po (3S LiPo's max. voltage is only 12.6 V, hence no need of additional regulator).
A regulator is needed only if yo are using anything bigger than 3S