this is my solution, not exactly light weight! It has given a problem with ground clearance but its in line with the lowest point on the exhaust which kept getting knocked off but i now have piece of mind im not going to take the sump off!
I also use fiesta 1.8d front struts and springs with one (and a half -thats another story)top mounts providing lots of travel and ride hieght.
the main guard is a mk4 astra (police issue) sumpguard - this web site has 1 listed - though you could make your own this can save a ot of mess on as it just needs about an inch trimming from the rear.
http://www.vauxhallworldparts.com/vauxhall.php?partnumber=13229999
for mounts
I strenghened the entire radiator mount by welding 25mm box to the shape and plate to the bolt mounts, the guard is then attached with exhaust mounts from halfords, basically 2 bolts with ruber in between to allow for a bit of flex.
I have another 25mm box at the rear running where lower strut brace goes, this is bolted in through the subframe below where the front arms go in, there are actually holes in the subframe in this spot already. As I bent this bar I then added another 25mm by welding mounts to the subframe so I now have two! the easier option is to utilise a lower strut brace as the rear subframe mount but you will lose some ground (25mm ish) clearence
