I think it's more of a complete engine tuning issue, rather than just the turbo.
Nissan have done a pretty comprehensive de-tune of the YD25 that they put into our D22's. A mate has an R51 Pathy with a YD25 in it & it's chalk & cheese to my D22 YD25.
It would likely be more cost effective to buy a more powerful 2nd hand car?
I realise that everyone is different, but I don't have any issues towing with it, other than taking off from at standing start on an incline when loaded up near the max. I hate slipping the clutch, so I have been known to stall it lol.