Wendy - never been to Frog or Ben Lomond so crack experience pretty much limited to the stuff on offer at araps and in WA (West Cape Howe and Margs have a few).
As an aside, we've been scouting around some of the local crags trying to find awkward stuff (preferably cracks) to experiment on. The most awkward lowish grade thing we've found so far was Half Man, Half Biscuit (17) at Black Hill. The bottom crack was soaking wet which didn't improve things. I climbed Mari for the first time on the weekend and thought it was much easier :) If you like to suffer a bit HM, HB might be for you. It's actually a really pretty spot at this time of year.
Back to Moab, Incredible Hand Crack and Supercrack do look amazing. A guide might be a good idea, if only for the use of their rack. I'm not sure my doubles of #2 and #3 C4s will cut the mustard!