I would have thought the F17 will have a lot taller 5th gear than the F13 from the Z14XEP so motorway driving will be better as the rpm will be lower for top speed.
I know that is the case on the UK spec'd SRI Corsa C anyway.
It depends what you want? Low rpm at motorway speeds or fast acceleration?
Are you planning to tune the 1.8 for decent power (250+) or leave it stock?
I have the F23 in my Corsa C and Tigra B and about to fit the 3.54:1 final drive to the Tigra as in the Corsa it helps to get the power down faster than the 3.94:1 final drive while also keeping rpm down by almost 1000rpm at 70mph.
I will be doing minimal mods and it works out to about 200 revs extra in fifth gear to have the close ratios and a stronger box . A pair of mild cams that the factory EFI could cope with would be nice and easy to do at the moment .