The Planning of an Exhibition

The planning and painting for my exhibition is well underway.
I like to get a general idea of the paintings as a whole, in the exhibition space.
I have given this a lot of thought.
My idea is to have a series of small paintings, only up to about 40x40 cm.
I like this size for these portraits or just heads of extremely interesting people I"ve
met for this project.
That's just the small part!
Plannings underway for at least three huge paintings which are the ones to create 
an impact on the viewer.
One of these is a "take" on a famous old master, I might go as far as up to around 
214 for this on the larger side.
The rest are also quite large.
The question is, what surfaces should I use?
The very large will have to be canvas or linen, simply because I just cant afford to 
Frame them!
Deciding what surface to use is extremely important to me. I love to work on panel
with oil and it is proving to be quite fitting for the images of tattooed people that I am working on as the paint glides onto the surface with ease.
To me a panel is the most appropriate surface for my studies in oil and egg tempera.
However, it can be used to great effect on canvas too.
As the oil and egg tempera technique is so lengthy, I have chosen not to use it for the whole exhibition. Also, it does not suit every piece.
Oil on panel, canvas and linen are my chosen medium for the whole show.
I make the canvas stretchers myself, and the painting I am beginning on measures 105x79 cm.
More on this later, I"ll keep you posted!