Do you have source code for either programmer? I'm not certain but I think the GTB-lite uses a 18F2550 and does not publish their firmware.
Good new is all of those crystal will work with USB, you'll have to set the config fuses as indicated on page 30 of the 18F2455 datasheet to set the PLLs
Without decent access to parts building a USB programmer might be tricky, I'm putting together a PICkit 2 compatible which is a fairly straight forward design, the pair of MOSFETs might not be easy to source but are actually optional the rest of the parts are common. It is designed for a 20MHz crystal but if you're interested and since Microchip posts the firmware I could try a mod it for a 4, 8 or 16MHz crystal for you.
**broken link removed**
This basic version works and is the 4 transistor (no BS250 or 2N7000 MOSFETs) I used a 18F4550 as it's what I hand on hand at the time.