I'm looking for some patio design software - come on, there must be some English stuff out there linked to various patio slabs on the market that can be incorporated into your design .... surely ??
As TVG has said Bradstone do there own patio and driveway design software. You should be able to download it from there web site or go to your builders merchant and they may have a hard copy on cd. They have all the ranges on the software and it will even give you a random pattern with a print out on quantities if required. Marshall do a garden visualiser which probably will have a patio design program in there.