Have you looked at Pier1? I bought my dining room table base there as I already had the glass top from my "first apartment" dining table 20 years ago.
I really like this one:
http://www.pier1.ca/canada/CatalogMe...e/Default.aspx but I think the style is not in keeping with the chairs. They do however have this base
http://www.pier1.ca/canada/CatalogMe...e/Default.aspx which might be a bit more cohesive. I think you could use a larger piece of glass and have it overhang the base at the top.
How many chairs do you have? Two or four?