Does this breed exist?

[PosiePootlePerkins]

Thinking ahead to a few months time when we will hopefully be in a position to get a dog. We would like a dog which is:
Friendly - we have two boys aged 7 and 12 and would like an affectionate dog
Not too big - can cope with a medium size dog but not a huge one
Doesn't need loads of exercise - could manage two walks a day but not long ones in the week. Longer walks at the weekends. We do have a large garden which we would dog proof.
Can be left for a few hours, up to 4 maximum. Would use a dog walker twice a week when I work until 4pm to break up the day. Other days I am in at lunchtime.
Obviously I know that each dog has its own individual temperament and personality but in general, do any breeds fit the above?
Thanks

A little-known fact about greyhounds is that they have magical telescopic legs. They can curl up to be amazingly compact - or spread themselves out like you wouldn't believe. My grey has a beanbag in the living room and she can curl up into a tiny ball in the middle of it, like an egg in a nest - or she can splay herself all over it with about 20 legs sticking out everywhere and her head resting on the floor.

My whippet is magic. She can hog the full length of a 3 seater sofa when it's warm.

But when it's cold she disappears under dps legs or behind his back. You might just see a nose poking out if you look carefully. Alternatively she will squash onto the sofa with me,dd and ds. She is the canine equivalent of a slinky.

My whippet is magic.

It's a breed trait

It's amazing how small they can fold up when they want to. If the mood so takes them my three whippets can curl up together in a heap so small they only take up a single space on the sofa. Of course it works the other way as well and somehow a single whippet can stretch out far enough to take up a whole three seater sofa

One of the favoured spots for DWhippet2 (and sometimes DWhippet3) is curled up on the back of the sofa wither their head resting on either mine or DH's shoulder. DWhippt3 can also make himself small enough to get completely under the sofa.

I wonder if Italian greyhounds have the same abilities. If so they could probably disappear entirely at will.