speak with matt at humphris nissan/seat or avanti or piper.
Matt will be able to supply you with what is in my opinion the best cams out of the bunch, wont give you the highest power rating but gives the power when you need it most. Will let you rev to 7750 with little problems once you get a remap, however they are the pricest out of the bunch iirc.
Avanti are pricey (£400), bit of a unknown as i've not seen them fitted. Heard that they are peakier than those supplied by matt and produce slightly more power, however the don't give the smoothest drive.
Piper are regrinds, send your old ones and they replace/regrind them. They do two types fast road and high performance, not sure what they are capable of though. Cost unknown but cheaper than the above two.
Finally if you ask James nicely he may sell you his Piper cams that he has in his room
Mike