I've been developing a mac OS X based PIC development environment that may work for your application. It is proceeding quite well and I am intending to release it as shareware in the near future (current planning is within the next 2 months). It supports nearly all 12-bit, 14-bit and 16-bit core PIC's, including those with USB-modules. The software also features an integrated assembler/disassembler for these chips but no higher-level languages like basic at this point.
With respect to hardware, I am currently using it with a homemade programmer (based on the once-popular mac based PIC programmer by Francis Deck, but improved to support more chips) connected to the USB port via an FTDI USB-serial chip of which I had a number lying around, which works well albeit not particularly fast. My plan is to include support for a number of the popular more modern programmers available (PICkit, wisp628, etc) in the next version of the software. I will also publish full instructions chematic/PCB etc. of the programmer I am using.

Wouter.