I have been searching for a month for some fabric like the 1st bag! I can't find anything like that anywhere! Do you know the manufacturer or designer?
That is by Waverly and it's often only available by special order. The color (black & white) is called Onyx and I think the pattern is "Essence". Last summer there were some curtains made by Waverly of this pattern / design, and they were called "Valerie". Linen 'N Things sold them, if you are extremely lucky you may be able to find some in the curtains clearance section at LNT for $10 or less for a panel. However, the special order fabric, if you get the "Sun N Shade" type, will be higher quality.
I would use a magnetic snap, but personally, I would open a hole in the bottom of the lining big enough to slide my hand up there to install it. This way you are sure to not mess with the top seam which you might see from the outside. That's how I install my magnetic snaps anyway, it's the last thing I do before sewing up my turning hole.
I like my purse to fit nicely under my arm, so I use 22" handles (measured end to end before sewing in, and I use .5" seam allowance, so they would end up 21" finished). Oh, and this is for purses that have 2 handles, one on each side. Purses with one handle are all different, depending on how it's attached, the shape of the purse, etc.