Why a combine as the power unitIJ Much better to get an old JD5830_NH1900s sp chopper,take off the pick-up and tear out the chopping box and put the mowers on the front of it.There are many of these self propelled mower outfits working here in the UK cutting big acres of grass silage and best of all the 30f mowers fold up to within 10_12 foot wide for legal road travel!!!!.It is a relatively easy process to convert the sp chopper to a sp mower.