With a car line up like yours, I'd be investing heavily in security for my house.
Be in the mindset of: "if they want it, they'll get it" and then rather look at what you can do to stop them from getting your cars, look at what you can do to slow them down - if you can slow them enough, they'll usually look for a less secure target.
CCTV is fine for showing the police afterwards, but it's not going to stop guys in ski masks.
I would invest in a set of removable bollards that you cement in to your drive (you may get away with just one if your drive is narrow enough). Whenever you come home, up go the bollards. This means that even if they do break in to your house and get the car keys, they've also gotta find the bollard key then run outside, take it down, get in the car and then make their escape.
I'd also invest in a composite front door with minimal glass, those things are almost impossible to bust through - even with the big rams used by the police and fire service. I know that for a fact because our neighbour is a fireman and if they come up against a composite door they'll go smash a window instead because they've been known to spend over 30 minutes trying to break one down.
If you've not got them already, have trackers fitted to the cars. A week after our TT was stolen off the drive our neighbour had his impreza knicked at 12pm on a Thursday afternoon while they were at work - broad daylight, they crowbarred his front door open and ransacked the house until they found his spare keys. When my neighbour got home for lunch at 2 and saw what had happened he got straight on the phone to the police and tracker company and they found his car within 20 minutes.
A steering wheel lock is another good idea, again it's not going to stop them if they have the keys but it's another 30 seconds they'll be delayed.
It makes me so angry that this is the type of thing that we need to do these days even in nice areas of the country to keep our property safe. But as you've experienced first hand, there are little scrotes out there who will give it a punt - so best to be as prepared as you can be.