Canada PR to USA, J1 or H1...?

hi, i appreciated it very much if you could help me.
if a Canada PR apply for a visa to USA, which visa is good? J1 or H1, or other else?

If J1, is there J1 waiver problem in the future? J1 holder will get tax-free income. but should he pay more tax to Canada?

If H1, he must pay tax to the USA, then he still should pay tax to Canada? Do you know the amount difference in the tax to both gov between J1 and H1.

for example, the annual income is $40,000.
J1: tax-free to US, how much tax to Canada?
H1: how much tax to US, and how much tax to Canada?

Thanks a lot