Well, the guidance for Radeon cards is as follows..
9800 < 9800SE < 9800 PRO < 9800XT.
You should base your decision on this, and also take into
consideration of pricing. A 9800Pro 128mb can be had for around £135
(
www.scan.co.uk) but you're likely to pay at least £250 for an XT
256mb. Personally, for price/performance ratio I would go with the
9800 Pro, unless you're loaded