Recommend me a Sealant. Metal and glass Conservatory.

[Magog]

Hi guys can someone recommend me the correct sealant to use for repairing a leaky conservatory. This is a rather dated cheap conservatory of metal and glass construction (single glazed), I'd like to make it a little bit more habitable as it lets in water when there is heavy rain, I only want to extend its life for a couple of years or so. Plan is to use some type of silicone sealant internally to try and make it watertight. Is this the right way to go, or does it really need to be done externally. I'd rather not do this as I can see it ending in blood and tears. Wood a roof and gutter sealant be a suitable solution for internal use?

http://www.screwfix.com/prods/67521/Sealants-Adhes...
or would something like this be more suitable?
http://www.screwfix.com/prods/62431/Sealants-Adhes...

Picture of offending conservatory below;

[chris1roll]

Glazing silicone:

http://www.toolstation.com/shop/Adhesives+Sealants...