Hi Ian...
My view would be, if you are a 1st time builder, and putting in a fairly standard engine / installation type, the Vans FWF is a good idea.
I doubt you could better the value locally. Additionally, if you take into account the research you would need to do, and ordering lead times, then I cannot see "local" getting anywhere near.
OTOH, if you have a non-standard setup, and/or know exactly what you want, off-piste might work...
HTH?
Andy
http://www.g-hilz.co.uk