Alternative Autos are usually the cheapest I've found for genuine kit:
CAM KIT 1.9 8V JTD (-AC) COMPLETE 2X BELTS,3X TENS £99.95
CAM KIT 1.9 8V JTD (+AC) COMPLETE 2X BELTS,4X TENS £119.95
CAM KIT 1.9 16V CF3 JTD (+AC) COMPLETE 2X BELTS,4X TENS £119.95
CAM KIT 1.9 16V CF4 JTD (+AC) COMPLETE 2X BELTS,4X TENS £129.95
all plus VAT and delivery
ALTERNATIVE AUTOS ,UNIT 11,STATION COURT
PARKMILL WAY, CLAYTON WEST,HUDDERSFIELD,HD8 9XJ
TEL 01484 865086 FAX 01484 865337
More details via 156.net - they sponsor on there......
fiat parts tractor spare motorcycle at shop4parts.com
are also reliable suppliers, as are Alfashop........
so I don't know which aftermarket outleys you've searched, as all these are well known......