I would do the 1000, has less ram and storage but unless you have small hands it is much easier to hold. The PSP is small to begin with, the Go made it worse by putting the buttons less than an inch apart.

3000 was the best in my opinion.

I love the Go but unless portability is a huge factor for you, I'd keep the 1001 instead. I mainly used the PSP Go because it fit in my pocket.

But I wonder what you mean by "keep for emulation", because PSP isn't a very good system to emulate things on. I remember even SNES games having bad slowdowns when emulating on a PSP, you might as well just buy a retro handheld than repair what you have.

Keep the 1000. Easier to find parts for. There's an IPS screen mod out for it. Could do a big battery mod. CFW is easy to put on there.

I much prefer the form factor of the go. The lighter weight the better imo. l'd go with whichever one feels better to hold.

Upgrading the storage on non-GO PSPs is as easy as buying a generic microSD to ProDUO adapter.