'iCruise' has advised you well. A few more things to note...
To be completely honest, I've heard few of the people on these boards say they've purchased through Dynamism. I think they are the most expensive. I don't know... their warranty, and localisation might be worth it, but the unit cost s lower at the
other places
Amazon.com usually has a few to offer (maybe used, maybe new...even NEW [sealed/unused] SL-5500s occasionally pop up). They currently have both 5500s and a couple 6000s available.
And while we're talking online, theres always eBay. 5500s are easy and cheap, 5600s not uncommon, 6000s basicaly rare, Cxx0 also rare but they apear now and again, Cxx00 are of course the most prolific right now.
I tend to think the online retailers are better. Though you might save some of the unit cost by using an online auction, usually not enough to mitigate the superior translation and warranty service that most of the online retailers offer (be sure you read the details WHEREVER you purchase from). Plus, one or two of the retailers offer little extras like a global power adapter and/or the usb host cable (both of which you will almost certainly want). I purchased through eBay and had no real problems with the unit or the deal, but in the end I didn't save any money (in fact I might have paid a little more than if I had gotten everything at once from a single merchant...)
All that said, it kind of depends on what model you want. There are rumblings that the C-3000 will soon (if not already) be put out of production, having been eclipsed by the C-3100 (it has 128mb of flash instead of 16mb, I think other than that and the chassis/case color they are the same). So if for some reason you MUST have a C3000, ebay may soon be your only option.
But, for the C1000 and C3100 all the options discussed above are possibilities, as they are both in active production by Sharp (though I don't think Amazon currently has any of the Cxx00 right now).
I probably don't need to mention (but will anyway) the 5500, 5600, and 6000 have long since gone out of production, as have the Cxx0 series of clamshells.
Don't forget about the '
Deals and Great Z buysDeals and Great Z buys' forum of this very site. Some people find the Z is not realy for them, and others like to try all the different models so they swamp'em around. It's usually used stuff, or tips to cheap prices for accessories onlin, but it's always worth a look...
Hope this helps...