I paid a mate a couple hundred to do the job + others (most steering / anti roll bar components, sump gasket, rocker cover and engine mounts).
The mainfold was taken to another friend at a garage to MIG weld new flexis - the public price was something like £50 a flexi. Not too bad.
All in all, a £1000 saving off the Renault price and the car is they way I want it again!
I wouldn't bother welding the flexis again though... Too much time was spent faffing. I'd much rather have a new manifold ready to bolt on.
RE: toyosports, if someone with a standard system could let the rest of us know what the performance regarding flat spots and noise is like that would be great for next time a flexi costs me £££.