Dulcimer Size ?

Hi All

I am wanting to order a dulcimer kit, the problem Im having is the ones Ive looked at are all a different in size.

What size should a dulcimer be?

One that Im looking at is a mountain dulcimer kit made by Music Makers.

4 strings

37 long

27 scale

2 1/4 deep

9 wide

$199.00

The other one is a mountain dulcimer kit made by Mc Spadden.

4 strings

36 long

28 vibrating string length

2 deep

1 deep sound box

6 3/4 wide

$140.00

Since I dont know anything about dulcimers, I would like some input, please help. Is there others out there that would be better to buy.