i don't think anyone has found everything needed on ebay, or all at the same hardware store.
the first 25 I sold, only the gauges and tire valves were from ebay,
the tees, hose barb fittings and reducers were all from an online store, and i had to buy in bulk bags of 25 each,
the hose and pvc fittings were from the local ace hardware, and expansion plugs for the exhaust blockoff from an auto parts store
i just received 25 sets of new parts and 6 gauges, and will buy more gauges as they sale.
for you to buy seperate parts from ebay.us and pay all the shipping/duties to the UK, you'll be way over the cost of just shipping one of mine to you.