My husband and I got married last year and found ourselves in the same situation, not only because we had everything for house etc but because we're both very much of the nature that if there's something we want we go buy it.
We had long debates with family (paticulary my mother-in-law) as she felt it was offensive to ask for money. So we simply didn't mention anything on invites.
As the time approached most guests asked my mum for gift ideas and she simply told people we had everything, however we were hoping to do some home improvements etc. All our wedding gifts were monetary in the end apart from one grotesque set of bath towels and some tatty ornament that still had the pound shop sticker on the bottom (suprisngly both from my mother-in-laws friends) now I'm not an ungrateful person but it cost �180 per head to have those people at my wedding.
So I would simply leave invites blank and make no mention of gifts anyone that cares enough will ask nearer the time.