Istabraq heads Champion entries Aidan O`Brien`s Istabraq heads 40 entries revealed today for the Smurfit Champion Hurdle at Cheltenham on March 12th.The 10-year-old, who will be bidding for a record fourth victory in the hurdling championship, is among 12 Irish-trained possibles for the Stg#270,000 contest on the opening day of the National Hunt Festival.Ned Kelly, Joe Cullen, Liss A Paoraigh and 2000 Rothmans Royals St Leger third Chimes At Midnight, who is so far unraced over hurdles, also feature in the powerful Irish team.The race had been mentioned as a possible target for another Irish ace, James Bowe`s Limestone Lad, but his name does not figure among the entries.There are two French-trained entries - Guillaume Macaire`s Jair Du Cochet and Bilboa from Francois Doumen`s stable - as well as the best hurdler in Germany, the eight-year-old San Suru, trained by Mario Hofer.A strong English challenge includes Bula Hurdle winner Valiramix, one of six entries for Martin Pipe, and Nicky Henderson`s Landing Light, who took the Pertemps Christmas Hurdle at Kempton on Boxing Day.Henderson`s Geos and Regal Exit, Ladbroke Hurdle winner Marble Arch, the well-backed Brother Joe, and 2000 Irish St Leger winner Arctic Owl, who has yet to jump a hurdle in public, also hold entries.Tim Easterby has entered Barton, who has taken well to fences this season and was an easy winner at Newcastle on Saturday, but his preferred target at Cheltenham is the Irish Independent Arkle Trophy the same day.Magnus and Stormez, two recent expensive recruits from France by Pipe, have also been given an entry, although both flopped on their British debuts.