Here is a link to all the SEVIS approved schools by state:
International Student and Exchange Visitor Program (SEVP)
I assume Shebles Riviera in Arizona? They are not on the list unless they registered with a different business name which happens occasionally.
Just had a look at their website, a 10 day IFR for $4,995? OMG
Do yourself a favour, don't take a short cut on an Instrument rating.
You'll never experience the inside of a cloud in Arizona, how good is that going to make you feel the first time you enter IMC by yourself?