You will find a large selection of JockStraps at Jockstraps.com.
Here is a sampling of some of their products.  Save 10% on any order using promo code ALLKINK
Free US shipping everyday on orders over $40.  $4.49 flat rate shipping for orders under $40. 
Worldwide shipping available, cost varies.  Jockstraps.com offers the entire range of jockstraps and athletic supporters including fashion jockstraps, classic athletic supporters, and jocks with cups.  They offer major brands such as GYM Jockstraps, Duke Athletic Supporters, McDavid JockstrapsCellBlock13 Fetish Gear, Maskulo, Locker Gear, Outtox Jockstraps and Fetish Clothing, Nasty Pig Jocks.