I want wider hips to achieve an hourglass shape. Are hip implants a good option?

Unfortunately you were initially misinformed when told buttock implant were “higher risk”. It is actually fat transfers to the buttock that carries the highest risks and death rate of any cosmetic surgical procedure (1:3000 patients). Nonetheless, here is what i can tell you about cosmetic hip implants. Please keep in mind that an in-person consultation with physical exam is first necessary before any legitimate evaluation or final surgical recommendations are made.

Although I encourage every patient to workout and live a healthy lifestyle, curvaceous hips is most often the result of the right genetics for the skeletal framework and fat deposits in the hip area. Take a look at some professional women bodybuilders and notice how they too have a depression in their outer buttock - because they are ultralean, not because they don't have well developed gluteus medius muscles.  In other words, unless you are genetically blessed with "hour-glass" hips, your only option for permanent hip augmentation may just be hip implants. Please read on for more surgical details:
Often buttock implants provide the added curve to the "hip-dips" that many patients are looking for.  However this is mostly when viewing from the back side. When viewing from the front side of the body, actual cosmetic hip implants can be placed either at the same time or instead of buttock implants. Unlike buttock implants, which should always be placed under/within the gluteus maximus muscle, hip implants are placed under just the fascia because no significant muscle exists in this region. However, because they are much smaller and lighter, their likelihood of migration is relatively low. Typical sizes range from 120-250 ccs but any size can be custom made and utilized depending upon the patients anatomy. 

In general I consider hip implants to be quite safe. Like buttock implants, they are made of soft semisolid silicone rubber. They cannot ruptured or leak and, therefore, can be left in place forever (unlike  breast implants that require replacement approximately every 10 years). In my experience the infection rate and incidence of seroma have been only ~1% each.
Unfortunately fat grafting to the hip area is frequently met with poor success because, again, there is no muscle there to place the fat into and thus is does not survive. Another thing is, if you are asked to purposely gain weight (i.e. fat) for the procedure, the fat you lose first as you get back to your baseline weight after surgery is that very same fat that was transferred into your buttock/hip...so don't fall victim to this recommendation.  Glad to be of help.  

While hip and buttock implants are in close anatomic proximity, they are also somewhat similar in terms of recovery. One difference is that wile there are standard buttock implants there are no standard hip implants. Ideally they have to be custom for each patient.