Recommendation for Pop'n Music handheld

Hi all!

Could you recommend me a handheld specifically targeted for Pop'n Music rhythm games? The machine must have the performance to run PS1, PSP, and PS2 (2D only) games—that is, all the games for which the subsequent Pop'n Music and Pop'n Music Portable installments were released.

In terms of physical dimensions, button size, and feel, it would be best if it were similar to the PSP 2000. I spent dozens of hours playing PnM Portable on that handheld, and it was very comfortable (once I found the right mapping of 9 PnM buttons to the PSP buttons).

Thanks!