Hmm, this type of questions are subjective.

Okay, first of all, what type of games do you want to play? What do you want to do with it? NDSL has it pros and cons, same goes for the PSP. But since you're asking it here, I'd say everyone here will tell you to get the PSP. Yes, its worth it.

The slim version which uses firmware 3.6, as of now, is not compatible to run homebrews since no one has it to mod/hack it in the first place (I think). But who knows, the homebrew community is huge, I think they won't have any problem modding/hacking/customizing the firmware. But how soon? That I'm not sure.
So, the question is now the fat one or the slimmer one? If you can't
tahan, get it now. If you can wait and you also need the extra feautures on the slimmer one, do wait for it. Or you can get a fat one, and later on, sell it and buy the slimmer version when it is capable of running homebrews.
Usually in Malaysia, it will be a lil bit expensive compared to the bigger ones. If you want to get it, I suggest you get it from Bernard.