Through the nipple breast augmentation is very popular in our practice with both the saline, and the silicone gel breast implants. The scar is hidden in the color break in the skin and the augmentation looks very well. The diameter of the nipple must be large enough to accommodate the implant; no problems with the saline, with a gel implant the nipple may need to be 4 cm, a fairly average size. There is no published data which shows a higher capsule contracture rate for periareolar implants, nor one that shows a higher infection rate. We have no infection after breast augmentation, though do see capsules form for a very few.
We use many Allergan 410 implants, however in the US they are not approved for breast augmentation, only for breast reconstruction so if they are offered to you this may be a red flag. The Allergan 410 is a 'form stable' implant which is less compressible than a regular gel. The incision required to place the implant is larger than the diameter of most areolas, so infra-mammary incisions are the norm. If the incision is too small and the implant is forced, it is possible to fracture the gel inside, and affect the performance of the implant.
Best of luck.