Visa is based on date of interview.
Class of admission at POE is a grey area: some CBP officers say it’s based on visa, but if you ask nicely they might note IR-1 over CR-1 to make it less confusing to USCIS if it’s been over 2 years at the POE and they enter IR-1. Others default to the date of marriage since that’s what USCIS uses. It really is an officer-by-officer thing what they enter into the computer. I would ask it be noted IR-1 if she enters after the 2-year anniversary, though to make it less confusing for USCIS. If CBP refuses, not the worst thing in the world, though.
10-year green card vs. 2-year green card is based on length of marriage at point of entry, regardless of what CBP notes as class of admission. USCIS is supposed to compare date of marriage to date of entry and make the determination based on that, but sometimes they don’t and default to what CBP enters. If CBP notes CR-1 since the visa is CR-1, USCIS might screw this up when issuing the green card. In that case you’d file form I-90 for free immediately asking them to fix it.
If your wife enters with an immigrant visa in your passport CBP will process her an an immigrant and she’ll be an LPR, even if you’d rather wait a few months so she gets the 10-year green card.