6n gearbox choices for afh conversion

[sixen]

im thinking about fitting a 1.4 16v engine into my 1L 6n. ive heared that the 16v gearbox is a bit of a screamer at motorway speeds, much like my 1L box, i hate it just over 4k rpm at 70mph it a bit annoying and not very fuel efficient. i have a gearbox from a 1.6 polo glx, will this give me what im after in terms of off the mark performance and a better 5th using the afh engine?

any help appreciated

TA