I don't think it is too late to have a homebirth - is your mw all for it then? It's not at all messy. The mw's bring sheets for the floor and they generally do all the cleaning up too. There are things you need to have, I think they give you a list, but they are common things like a sponge and bowl, etc.
It's much more relaxing than at the hospital, you can have your fav. music playing, candles and insence burning, a nice cup of tea afterwards etc. I had my second at home, he was born at 6.22pm, the mws stayed until I was bathed and he was fed and we were both comfy, then one of them was back again first thing in the morning, so the care is really good. You can try different positions too.
Get in touch with your local NCT, they might be able to arrange for you to have a few quick sessions with their ante-natal teacher - vital for a homebirth! They tell you stuff that NHS classes don't tell you, like for instance that if you squat you can actually open up your cervix by another 3cm! They know all the techniques and tips for a quick and stressfree home birth. They could even lend you some equipment like a birthing ball (I gave birth over mine, it gets you into the ideal position and is wonderfully comfy!).
If anything goes wrong, the mws won't take any chances and you'll get to hospital in probably the same time as you'd be carted to theatre in a delivery suite.
Go for it!