Protein Skimmer recommendation/help

Dear Ma'am or Sir:

I would like to purchase a Coralvue protein skimmer for my 100 gallon saltwater tank, but I am faced with the following complications:

(1) I do not have room for a sump.
(2) Mine is a custom tank with a 4.5 inch lip all the way around the top.

It seems to me that I need either a hang on back skimmer which can be extended enough to go the distance of the lip, or an in tank skimmer with a strong, adjustable clamp for the lip. There is enough room behind my tank for a stand alone skimmer (is there such a thing?), just not a sump (the space is only 11 inches from the wall).

Can you recommend a protein skimmer for me? I can lengthen the piping for one of your hang on back skimmers if you sell the parts.

I appreciate your time and look forward to your reply.

Regards,
Grant Lasiter