John,
The trouble is not so much matching the lug pattern but getting a set of 4 wheels to match especially as the rears are not only a bigger radius but width too.
Most popular styles of wheels can be ordered in a selection of sizes, the wheels that I put on my car (only temporarily) were appartently availible in the correct sizes.
A picture of these wheels on my car can been seen on the opening page of my website www.dmc12.co.uk
15" wheels with low profile tyres fit the front nicely and 16" wheels would take up some of the horrible wheel arch gap at the rear.
James