Ok. The first thing I would say here is that you need to discuss this further, as a priority matter as soon as you can, with a reputable firm of IP's.
You should also be aware that your wife and her finances will be a factor, one way or the other, so it would also be wise to have a full list of ALL income and outgoings, whether your wifes' or not, to hand so that you can be advised properly.
For a good idea, you may wish to visit
www.iva.com and have a look round at some reviews etc, I also suggest that you contact 2 or 3 firms to get a balanced view.
To answer your very first question, an IVA, if appropriate for you, can allow you to keep the flat and the business but you definitely need to speak one on one to a professional.
Hope this helps.
Regards.