The PSP-1000 series might have a smaller amount of memory, but it's construction is good (Figures, it has a metal frame in it!) and it's battery is superior to all other console models (1800mAh vs 1200mAh).
Originally Posted by flo
Even if it has 32 MB of memory, most homebrew software will run fine on it.
I have not come across any homebrew software that will only run on newer consoles yet.
If you can get the Sony extended battery (2200 mAh), that's even better!
PS: You can't really say that all consoles are indeed "hackable".
Only the PSP-1000 and PSP-2000 (Excluding the model with a TA-88v3 mainboard) series of consoles can have a full custom firmware that uses a modified IPL.
The latest CFWs that use modified IPLs are 6.35 custom, 6.37 ME and 6.38 ME.
The other consoles will have to use a HEN (Homebrew enabler) instead.
Some HENs are permanent (Like a true CFW), and will still allow you to launch homebrew again after power was lost and restored to the consoles.
Others will require you to "re-install" them into RAM.
Unmodified SCPH-77006 with SM 3.6
SCPH-39006 with M-chip modchip, SCPH-10281 NA and refurb Seagate 80GB HDD
SCPH-10000 v1.00 with SCPH-10190 PCMCIA NA and SCPH-20400 HDD unit