i actually use a product that's not exactly a tinted moisturizer, but a cream with added color and defense properties... it's called Skin Food BB Cream. also known as a blemish balm. you should definitely look into it. it's triple functioning with whitening, anti-aging, and sunblock (spf 20) effects. i've been using it the past two months and have noticed the texture of my skin improve and spots lighten. i just apply it after my moisturizer and it adjusts to match my skin tone. i usually wear it alone or under mmu. however, there are two downsides:
(1) korean product, usually found at korean cosmetic shops, or online (try eBay)
(2) only two shades (i would only recommend it if you were lighter than NC40)
HTH!