Last update on this. I put the gators on last night and tested them. They work very well. Not quite as well as a mulch kit. On the other hand, $400 on a mulch kit vs. $50 on the gators leaves a $350 difference. The mulch kit wouldn't be $350 better.
Also, there is no mulch kit for the RCK60-24B Kubota deck. The dealer in Reading was claiming that the deck is the same as the 60" deck for the BX. Now the BX deck has different mounts, wheels, etc., but the deck itslef is supposedly the same which will accomodate the mulch kit.
I hope this can help someone else out.