try this link for user instructions for the dt10rf optimiser
http://bi.worcester-bosch.co.uk/index.php?fuseaction=literature.detail&con_id=231279&from_id=5029
just for labour i would say £750, boiler and fittings would come in at about £950 with vat so if i was a plumber an all in fixed price cost would be about £2k maybe £2250 to cover for any x-factor turning up.
I would use plastic, you would have to use a barrier pipe to stop the ingress of oxygen into the heating system so would recommend the hep2o barrier pipe which will leave you no joints under the floor so once installed you can forget about any potential leaks.
Can anyone give a quick answer to the difference to end feed and yorkshire endex fittings? i thought the yorkshire fittings came with the solder ring but endex doesnt does it? also are there any cheaper solder ring fittings other than the yorkshire range? :roll: