Don't get a 9800. There great but its to late, suppourt will drop drop soon. Don't get a 9810 because suppourt will drop too, and I don't think its very good value for money as a 9800. Amazon has both for expensive prices. I'd say wait till BB10 then decide, prices will fall too
9800 is a great phone and you can get one for a great price. RIM shows several older phones as "current", including the 9800 so I'm sure they will continue to support it for a few good years.