hello mate, you can get a magnetic sump plug here
http://www.awesome-gti.co.uk/product.php?xProd=6807 worth paying for for what it does at that price

and most people put new plugs in anyway each service

lol so you could just keep that and then not have to worry.

as i said earlier, flushing your car will be fine as long as the oil has been changed at sensible times. if it hasn't been done for say 30k , 2 years or more then that's when you could run into problems as all that crap will be broken up. irronically we had an a3 that hadn't been done for good knows how many years. used a flush and that fooked the pump as the strainer would have got blocked. so as i said as long as its been done regually then it would be fine as there wouldn't be enough crap to suddenly block it.
magnetic sump plug above
5/40w snythetic, not 5/30 synthetic castrol edge, too thin for 1.8ts on high mileage! 5/40 they sound quiter
and replaced oil pick up pipe. as pumps are known to go on 1.8ts. simple, just undo all the sump bolts, 2 are a pain by the bell housing. and clean out the sump, and replace the pick up pipe, just 2 bolts! you'll be suprised how clean your engine oil is after.