Making my own pcbs the other day I had a hard time finding a 16hz xtal with parallel 22pF caps through mouser but I did find a 16mhz xtal and it specified in the paert description parallel 18pF caps so on a whim I went that way and just picked up some 18pF ceramic caps. It worked flawlessly. So my marginally educated opinion is that a xtal with 22pF caps isnt entirely mission critical. As long as the parts that are used match up (the xtal is used with the caps specified by the xtal) it should be ok.
B