bed floor question

[mrh]

guys, I'm building a 67 swb stepside gmc that had a wood floor. this truck (bed) will see alot of use so I want to go back with a steel floor. there is a complete swb bed (fleetside) local I may can pick up for $100.00 with a good floor. I want to keep the stepside and use the steel floor. I know I will need to change the bed front panel but would the side panels interchange? as far as the steel floor goes, doesn anyone know how much would need to be taken out of the middle to make it fit? am I nuts for thinking of doing it this way?

thanks