I have always wanted to do or see someone do the front clip idea.
I would start with a bed and remove the outer fenders. cut the wheel wells out to fit the lenth of the fenders then cut and add the tailgate bulkhead to the box. Then femove all the inner structure of the front fenders and graft them on. blending the slope of the top edge of the fender to the bedrail is probably going to be the toughest part.
You will hve to leave most of the top part of the bed i assume, cuz the fenders are thinner than bedsides.