Personally Id probably got the A600 option (or an a500+), for the sole reason of there being more available chipram (1Meg vs 2Meg). Additionally Id advise on a harddrive as well (which is part of the reason I suggested an A600..... cheaper and easier to install a hdd in an a600 than an a500).
I had Amiga 600 with accelerator and Hard Drive back in 1999 and it was overheating too fast, that it forced me to place the harddrive outside of the machine, but it was still overheating with 68030 CPU inside.
The A600 also had problems with slower serial bus when using resolution with higher depth (32 colors and above). I don't know if it will affect the MIDI, as the MIDI speed is not that fast anyway. There are some serial.device replacements on Aminet, but they did not help much. I still wanted to use Amiga back then, so I bought Amiga 1200 that solved most of my A600 troubles, with the price of being able to watch AGA demos and play AGA games. Also Digibooster does not work on 68000, but works on Amiga 1200.
