ATmega32u4 Custom Lilypad USB, how to load bootloader?

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Hello All,

I am planing on using a ATmega32u4 and replicating the Lilypad USB schematics but I cannot see the SPI port to load the bootloader in.

So it got me wondering, is there a way to program the bootloader directly through the USB?

I was planning on buying this one:

Or the RC version but it I am not 100% sure it will work properly at 3.3V with the USB.

Thanks All!