You can always find somewhere to leave cars, we use a Tesco car park at the moment.
We had some bad luck a few years ago and ended up living with the inlaws. We too could not afford the type of house we were used to (nothing special, but a 3 bed semi in a quiet area). My wife suggested living on a boat and I laughed, " you can't live on a boat!!" Sure enough though, you can and people do, so we did. I always tell people it blind sided me, I had no intention of living on a boat but I cannot believe how much I enjoy it.
When we bought our boat, I had no real experience, apart from working on my cars up until then. I have however since then taken part in the two college courses that Reading College run, Electrics for Boaters and Marine Diesel Maintenance.
This may sound a little odd, but things to look for, or at least I will be on my next boat are:
Water capacity - We only have 50 gallons and need to fill up twice a week.
Some kind of fixed bed - After 2 years of packing our bed up and setting it up, we have had enough.
A Bath - Showers are fine but I miss being able to have a bath.
Engine - We have a BMC 1.5 which seems OK and closely resembles (well, they used to be) a car engine.
Construction - I would not entertain a narrowboat that was not all steel, apparently it is difficult to seal the superstructure to the hull if only one is steel.
Heating - We have a drip fed diesel heater and I think it is great, it would be perfect if it had a back boiler and fed radiators and supplied hot water.
Hope this all helps.
Let me know if you want any further info and I will do all I can to help.
Thanks
Mike