PIC programming

[Peter Korsten]

Has anyone of you ever built a dedicated PCB using a Microchip PIC 
microcontroller?

The reason is that I'm thinking of building a pretty simple PCB using 
this chip:

http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en533924
(or the 18F13K50, which has slightly less memory and is slightly cheaper)

This PCB would present itself as two USB devices, and provide two serial 
interfaces. Hence the choice for PIC and not AVR, because Atmel doesn't 
seem to have MCUs with built-in USB support in a PDIP package, and I 
don't see myself soldering an SMD component.

Not simple serial ports, though, as you might expect; one of them goes 
to some sort of bus system, where there is no master and any connected 
device can start transmitting at any moment. There would also be 
opto-couplers involved.

(Heck, you could make a low-cost MIDI interface with this thing, but 
that's not the application I have in mind.)

Obviously, I would be experimenting a bit first, switching on LEDs and such.

Anyway, the chip is one thing, but it needs to be programmed as well. 
And that's where my question comes in. Basically, I have three choices:
1: Build a programmer myself. But the designs you find on the net are 
usually not for 20-pin and/or PIC18 devices.
2: Get the PicKit2 programmer for some $35 + shipping + tax.
3: Get one of these kits for some $50 + shipping + tax.
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en023805

What would be the best option? It would really be an exercise in low 
cost, but I would also like to retain the option of building and 
programming a couple more and selling them.

- Peter