You've already got the best strengthening treatment -Aveda Damage Remedy. Believe me, it blows everything else out of the water and I've been hairdressing for a long long time. I have used everything (and fallen in love with it too) but what surprised me with Damage Remedy is how well it actually worked. Better than even Redken Extreme (which up until using Aveda Damage Remedy was my previous favourite from the ones I have sampled throughout the years). And a note here for Bluerinse (as I just know he'll be eager to tell you about Biolage Fortetherapie) - Blue...seriously, Damage Remedy is Fortetherapie on steroids mate!! Try it...you will be amazed!
A product line I haven't tried is Pureology and I hear good things about that from Persianista.
For glossing, Universal 0N really cannot be beaten especially considering you can add pigment for a temporary coloured reflect, but if you are looking for a treatment I would say Hair Botox by L'Oreal (especially the one for fine hair) gives amazing natural shine that lasts.