First of all, they're your cels and do whatever
makes you happy.  That's the important part.

I wouldn't do it myself.  First, it's a
commitment to keeping them together, no matter
what.  That means that you'll need a huge space
to place the framed piece, which depending on
the arrangement of your living space could
narrow your options significantly.  As a few
others have mentioned, framing them separately
allows freedom to hang them together or apart.
I'm a bit of a minimalist when it comes to
displaying my cels...usually only one per wall,
so your opinion may vary.

Second, I'm not sure how much you sell or trade,
but once you do this, it'll be that much harder
to part with them (which may be a good thing) and
you may end up with a useless (and very
expensive) frame or being unable to make a 
trade/sell that you'd love to do.

Third, it seemed like a lot of your cels were the
normal sized cels.  If you're doing that, you can
frame them yourself using precut mats, etc for a
lot less than getting them professionally framed.
Plus, as an added bonus, if you get tired of
seeing the same cels over and over, you can easily
swap them out with others.  It's a fairly simple
procedure to do.  Ask Baakay...as part of her
recent birthday present, I bought her the
materials to frame her Bloodberry cel and showed
her how to do it.  The only time I get one
professionally done is when it's an odd size so
that the cost of materials is nearly as great as
having it done professionally...such as my BGC
2040 pan cel which I'll attach a picture of.