This is funny, because I was going to convert model either New York or London at some point. Although that's a task that I can't tackle right now.
Yes, you're right,with such a massive city to work with, this will be very hard to load on some computers, because of the way that SLRR loads its objects and maps. Because of its view distances as well, you won't be able to see very far of the city in the game either, if you know what I mean.
Look at the other Liberty Island (from GTA III,this one)and how long that one took to load. That wasn't very big, either
If you want to put bots in as well like Valo, that will be difficult. idk how big it is compared to Valo, but I'm pretty sure it's bigger.
It's a project that's possible though, and I'm looking forward to some shots of it.
And yeah, GTA meshes don't always convert the way you hope they do...