How much all in good nick? with tyres or without?
When I onced wanted something weighing I went to the local recycling plant(tip) as they have scales for weighing lorries in and out.Buy the chap a bacon barn and he will probably oblige.Worked for me anyway.
If you have the wheels the part number, et, size, width are all stamped on the back of the alloy.
You don't need to worry about weight as the numerous delivery companies on ebay usually charge per inch size of wheel.http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l2736&_nkw=wheel+delivery+service