IS this something we need to book ahead of time (April 3, 07)? The cost is tremendous with all the fees. There seems to be several different times, altho they are different costs.
Also, does this mean we will pay a surcharge if we miss a connection and take a later train?
Thanks for help.

If you avoid the Thalys trains Amsterdam-Antwerp then all the trains involved are IC or regional trains that don't require reservations and you shouldn't have any problem - can always get on and rarely wouldn't have emtpy seats. Thalys require reservations and cost more (except for special discounted and hard to get fares) - so just take the hourly IC trains Amsterdam-antwerp then go from there via Lille to Calais - check www.bahn.de for schedules and types of trains - if the words Thalys appears avoid that train. www.bahn.de is the German rail site that i've found easiest to use and has schedules for all of Europe. An easy way to reach the English language schedule page is to visit: www.budgeteuropetravel.com and on that home page click on the link All European Railway Schedules and you'll get the English language schedule page of the German rail sight - the home page referenced also gives several valuable tips on using the German rail site - for example highlight details under each schedule and you'll get info on the trains involved, whether reservations are compulsory, etc.
But back to original Q - no just buy your ticket in Amsterdam (easier to do at Schiphol Airport train station with few lines than at hectic Amsterdam Centraal Station where you could wait hours in line.

We will be coming off a Viking river cruise so unless we travel to airport, I guess we have no real choice.
Thanks for the help.

I think you would buy that ticket in the "international" office at Centraal Station and I disagree that you'll likely "wait hours in line."

I've been going to Amsterdam every year since 1969 and always spend time in the train station since i'm interested in all things trains - and there are usually, not rarely long long lines at the international ticket window in Amsterdam Centraal Station - that's a FACT!

Dukey - i'd be interested in why you disagree about the ubiquitous long waits in line at International ticket window in Amsterdam CS? What's your experience? Have you ever been to that office - apparently not very much or you would not say that. Even last December there were long lines there. Well i stand to be corrected if there's been a sudden change over what i've seen many many times for decades.

Can we buy the train tickets upon our arrival at the airport - 10 days prior to our needing them? Seems the best solution if it is possible.

Yes