Hi,
I think you can populate a standard 20 pins male JTAG connect on your PCB board with 100mil pitch, you can use J-Link or the other device to download/debug the board of LPC1768.
This is the 20 pins JTAG connector pin assignment.
Hope it can help you
BR
XiangJun Rong
To program for the first time, you can use a debugger, connected via the SWD/JTAG port, or use FlashMagic to program via the USART.
For the debugger, you will need a debug probe, such as LPC-Link2 or the new MCU-Link, which cost about $15 each and to use the free MCUXpresso. You will also need the SWD circuit described here
https://community.nxp.com/t5/LPCXpresso-IDE-FAQs/Design-Considerations-for-Debug/m-p/469565
If you are going to write any code, having a debugger will save you a lot of time, so it is better to make sure you can use it from the start, rather than have to re-engineer you board to add it later.