Your best bet would be to find a portfolio lender whose niche aligns with your investment strategy.

My wife and I have overhauled our personal budget to reflect the 'pay yourself first' approach (allocate in order: income comes in -> invest -> donate -> fixed expenses -> variable expenses -> fun $$).We are looking to see what experienced people generally recommend for a holding tank for that 'invest' allocation while we target our first real estate deal.What financial vehicles have you guys used that works well for this?

This sounds like good information.

I think they contain solid information and will help lay a good foundation as a beginner (Haha, I'm completely new to real estate as well, btw)I'm also going to be reading the following books, and hopefully I can finish all by the end of this month:1) The ABCs of Property Management2) The Advanced Guide to Real Estate Investing3) Long-Distance Real Estate Investing How to Buy, Rehab, and Manage Out-of-State Rental Properties (this might be the most important one to me personally)4) The Book on Investing in Real Estate with No (and Low) Money DownIn addition to reading, I'm consuming crazy amounts of youtube videos, and I'recommend you do this as well.

@Benjamin Carver great post with lots of helpful information.

2) I bet you could draw that same or even more extreme graph for new car prices.

Clearly, shes not happy and an unhappy tenant usually results in more issues down the road, and you can bet they'll be expensive issues. 

If so, do you know the area well? 

Sounds like their combined income likely beats your other tenants.Your gut is probably your best bet and you need to go with it. 

It's definitely possible to get a loan as a foreigner but the rates will be high(er) and the downpayment required will be as well.