Recommend IC for power supply 230/ 5V 400V 20W

I design power supply for electric fence.

Primari voltage 230V AC
1 Secondary +5V <100mA for control electronics
2 Secondary +400V for charging 70uF capacitor, capacitor must be recharged in less 1s

Other conditions and pitfalls
Control electronics must be able to source block for time <1ms, ie after the time when the capacitor discharges through the triac.
I suppose feedback through secondary +5 V supply should deal with the situation when after switching will be the second new work in the secondary circuit thus discharged into C 70uF.
My first design use UC3842, all work fine, but effectiveness is not very good and overall, my 3842 comes obsolete.
Can recommend modern designers, I wondered about TinySwitch-4 (Power Integration), but I do not know whether it is suitable?

Thanks

You want to kill people!

No, watch goats.
70uF capacitor at 400V 5J gives a normalized pulse energy for fencing the cows and horses or large enclosure.
Normally they even fences with enegry 11J and these are safe for cardiac fibrillation. Although 10J strike is already an experience of a lifetime