I think Polished Bliss sell it all.
This is taken from their advice section on silver cars:
Q. WHAT IS THE BEST SEALANT OR WAX TO USE ON SOLID WHITE AND LIGHT METALLIC/PEARLESCENT COLOURS?
Many people find it difficult to achieve an excellent finish on solid white and light metallic/pearlescent colours, no matter how well they prepare their paint. This is because the lightness of tone precludes a high degree of reflectivity and thus makes it hard to achieve a finish with any real clarity and depth. Furthermore, this lack of reflectivity can also limit how wet the paint looks, as fewer highlights are shown up in the finish. However, these problems can largely be overcome by choosing a synthetic polymer sealant instead of a natural carnauba wax as the last step product. This is because sealants tend to lay down an exceptionally smooth, highly dense surface coating that reflects light far more efficiently than a microscopically rougher, less dense natural carnauba wax coating, and this can add a significant amount of wetness to the appearance of the paint, as more highlights are shown up in the finish. Moreover, the same smoothing properties also minimise any scattering of light caused by micro-structures in the surface of the paint, meaning that reflections are afforded greater clarity and depth, and that metallic and pearlescent flakes receive more transmitted light and thus appear to stand out more from the base colour (a phenomenon commonly referred to as flake pop).
Out of the various synthetic polymer sealant systems we stock, we favour the Werkstat Acrylic Kit for optimal results on solid white and light metallic/pearlescent colours. This is because it delivers an incredible level of reflectivity characterised by amazing clarity and depth, and makes metallic and pearlescent flakes stand out from the base colour more than any other product we have ever used. Indeed, on some light metallic colours we have worked on, it has literally made the flake appear to explode out of the surface of the paint when viewed in direct sunlight. Further benefits afforded by the Werkstat Acrylic Kit include terrific ease of use, even in cold and damp conditions, and excellent durability, with a single application of the three component system typically lasting for around three months on a daily driver, although this can be extended almost indefinitely if regular quick detailing is undertaken. If your budget is too small to stretch to the Werkstat Acrylic Kit, there are two alternative options worth considering. The first is Blackfire All Finish Paint Protection, which delivers an equally intense wet looking shine, albeit with a little less flake pop. The second is Poorboy's EX-P Sealant, which delivers a sharp wet looking shine with good flake pop and offers excellent value for money.
http://www.polishedbliss.co.uk/acatalog/choosing-paint-protection.html
Other than that, waxes I would recommend are most of the stuff out of dodo juices range, try light fantastic should work good. I have a pot of poorboys natty's paste wax for light coloured cars you can buy off me if you like ha. Overall I would buy collinite as it is a good all rounder and if your not really into detailing it's not stupidly expensive!
