About many ways to say something?

Spanish native, so sorry if my english is bad.

I'm very beggining whit the japanese. The doubt is this.

I want to say "Mi hand is big".

These 2 sentences are right? Meaning the same?

1) watashi WA, hand GA big
2) watashi NO hand WA, big

And if I want to say that "My dog is big"

3) watashi WA, dog GA big
is ok? or need to say:
4) watashi NO dog WA, big

You want to say �gMy hand is big,�h then
Watashi = I
Watashi no = my
Te = hand
Ooki = big

1) Watashi wa te ga ookii.
2) Watashi no te wa ookii.

The first one is �gI have a big hand/I am big in the hand,�h and the second one is literally �gmy hand is big.�h

If you want to say �gmy dog is big,�h then
Inu = dog.
You can say:
4) Watashi no inu wa ookii

As �gmy dog�h is not part of you, you cannot use the construction 3).

as one of Japanese and I am not language teacher, I think "watashi wa te ga ookii" is probably irregular usage, but it is often used especially in conversation.

explanation 1:
"te ga ookii" is one sentence. the verb of watashi (subject) is abbreviated.
I am "my hand is big". = I am in the condition that my hand is big.
anata wa te ga ookii.= you are in the condition that your hand is big.
kare wa te ga ookii.= he is in the condition that his hand is big.

explanation 2:
watashi wa te ga ookii.= watashi (ni tuite) wa, te ga ookii.
about me, my hand is big.

although the meanings are not much different,
sentence structures are completely different.
in explanation 1, watashi is major subject and te is sub-subject.
in explanation 2, te is (major) subject.

I think , when we write logical papers, those kinds unclear expressions will not be used.

Thanks you both for answer, has been greatly help to me. The Japanese looks easy, but when you have a doubt, it's very difficult to find good answers. Thanks again.