With the monthly rent going through an escrow account via ACH.

Aside from providing the basics (ie. listing tool to get the property published to 10+ major sites, scheduling tool to schedule viewings, tenant screening with comprehensive applications -- pulled reports from TransUnion, which include nationwide criminal background checks + credit checks + eviction history, digital lease creation tool, rent collection tool, and maintenance tracking tool), some services also offer your tenants waived ACH fees and additional capabilities which makes it an easier sell on your end when getting them to transition over (ie. their ability to report on-time rent payments to the credit bureaus; this can create an added incentive for making sure they pay that rent on time).

ACH payments can be rejected. 

I use their tenant screening and ACH stuff too to automate my rent collection. 

After a many, many deals it becomes second nature and part of muscle memory.

I am not sure on the down payment how that would or should be handled but the garage could be a head ache for you.

Can anyone suggest a national bank with free checking accounts and that is landlord friendly in terms of no charges to receive ACH transfers.

Doing rehabs and aiming for other investors wanting turn-key properties just eliminates  a lot of head ache it seems.

How does it work with ACH rent payments?

They focus primarily on businesses and do real estate loans, unsecured lines of credit, will allow you to ACH tenants, etc.