The truth is, about 99.5% of lenders who offer conventional mortgages in the US won't lend to someone who isn't based in the US, even if that person is a US citizen living abroad or works for a US company.

If anyone has any insight or suggestions on whether to obtain lending from Canadian or American Banks it would be greatly appreciated.Also my wife is an American citizen.

If the American citizen only knew!

I am a US citizen working overseas and wanted to buy an investment property in the US.

Did your agent approach Citizens? 

Second problem is we are Canadian citizens, staying down in the US fir 6 months per year, so no credit score down here or SSN.  

It also goes against the narrative of ever US citizen should own a home mantra .. this will of course harm some minorities big time and as you noted those looking to max leverage their way into the home ownership.. 

Need to change that before there's a ban on French citizen...IRS is a pain, been struggling with the accountant for a year to get an ITIN and be able to pay taxes...

Are you a U.S. citizen?  

As I am neither a US citizen nor a resident, I would like to know which taxes I need to pay and which rules I need to follow.