...and I agree with Steve; considering the locale, the water just isn't going to go away.
Under the circumstances, the sump would be futile; it would probably run 24/7 and all it would do is raise your electric bill. The best you'll do here is to cover it up, Gary, so we're back to sand, dirt or concrete.
If I went with the concrete, I'd use a special mix (which I can't think of the name just now), that's a lightweight flowable filler; it's not used structurally, but more often for filling voids below slabs, etc. Your concrete provider will know what it is, and it can be pumped in and leveled in the same manner, but it won't be such a chore to handle. Plastic beforehand would be good, too.
If I did the soil or sand, I don't think I would use plastic, but possibly look into some powered ventilation which would boost the airflow through the crawl and raise the evaporation rate. There are crawl vent fans made for this of application.
As to getting the sand into the crawl, I think I'd look seriously at the possibility of removing the crawlspace vent covers, and chute the sand in at as many vents as possible; this would give you piles distributed around the inside which could then be raked out.
Either way on this one, Gary, it sounds like your last step in this project will be, as a colleague recently said, to treat yourself to a good massage!