uManage generates a complete check, including the check number and MICR line so all you need is blank check stock to be able to print a check locally. Even if you outsource check printing it is recommended to have some check stock on hand in case you need to print a check immediately. The default check templates are configured with 'Check on Top'. 
Blank check stock can be procured anywhere but here's a link to the check stock on Amazon:
Amazon Check On Top Blank Check Stock
Here's a link for window envelopes that align with the default check template: