Hi Achbar -

I have a reasonably large hands, with relatively slender fingers. This makes certain chords easier, for example making a D5 out of a standard first position D major by placing my small finger on the first string, 5th fret.

I think in general bigger hands means easier playing - though for people with hands that are thicker there may be some issues for certain chord shapes. I think you will probably find ways around that as your playing improves.

At Irish music school this summer, I took a class from John Doyle, the Irish guitar wizard. He has smaller hands than I, with slender fingers, and he can reach stuff that I still haven't been able to hope for!

There are also significant differences between guitars with respect to fingerboard size, shape, string spacing, etc. This is very personal but also relates to body size & hand size.
This is a long discussion so for now I will just suggest to try different guitar makes and models as you cruise your local guitar stores.

Have fun!

-Rutger