To be fair it doesnt really matter, you want as short a pipe run as possible ideally, but as straight as possible also, with minimal bends. Dont go for any that have a load of samco hoses joining up various bits of straight pipe. There are quite a few 'hybrid' copies on ebay. I've had one on mine for years without any ill effect. You might want to upgrade the hose clips though, cos the ones that come with the kits arent all that great!