DVD Recording and long or extended play compaibiliity

[T4R]

I have been asked to record a recent golf tournament from a Sky+ box onto DVD. I'm trying to find out if it's possible to record using an LG DVD recorder (model DRT389H) making use of its long play facility and playing it back on a Panasonic (DMR-EX77). This would give me roughly four hours per DVD -RW as opposed to two at normal speed effectively halving the number of disks required. I don't believe the loss of quality will be too noticeable. Is it a realistic expectation or should I stick to normal or standard speed mode ?

Many thanks