Spoke Size / Spoke Length Database - What size spokes do I need?

i have used the damon rinard spoke length calculator exel spread sheet http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3524 and have come up with 281.1 mm spokes.

for the wheel im using a on one front hub
large flange track hub

        front
        hub flange diameter: 61mm
        flange distance: 34/34
        locknut flange: 16mm

and a rigida dp18 rim, the measurements for which are in the calculator.

was going to order the spokes from parkers when i buy the rim to save postage, just wondered if someone with some experience of wheel building could run the measurements to make sure i have got it right and not messed up! i have laced a couple of wheels, but have no experience of purchasing spokes so any help would be greatly appreciated! plan is to lace and roughly true it, then hand it over to the lbs for fine truing, saving me pennies on wheel building!

its to match the wheel i have just purchased so i have a set to go on my new project, an old alan frame