To buy for her? Adoreme.com Sizes are on target, and they have new things every month. Lingerie of all kinds. Corset. Bra/Panty sets. All kinds of stuff. They are sexy and so cute! I love their stuff. First set is 25$, free shipping. And their outfits average 50$ rest of the time, which is awesome, cause VS is always closer to 100$ Everyone is different, so pick something you'd like to see her in.
I prefer role play with costumes involved. Something fun would be buying her a sexy red dress and having her meet you at a bar. You could pretend to not know each other and you go in and pick her up. Have a hotel room ready. The bar could be in a particular hotel. On the bed could be another outfit for her to put on. Have some fun.