In general, it's not the type of breast implant that makes the difference in filling in the upper pole of the breast, it's the size/volume characteristics. If the implant is sub-pectoral and round it will look the same whether it is gel or saline-filled.
Fitting an implant to a breast is a little like fitting an orthopedic implant as for a hip or knee. It is also like fitting a body to clothes or a foot to a shoe. It is not possible to just pick a size of hip implant, dress, or shoe and make it work. The key is knowing what fits and what effect that implant is going to have on the contours above or around it.
A round implant whether silicone gel or saline-filled will fill the upper pole of the breast properly if its diameter is matched to the width of the breast and the upper pole scallop is not taller/longer than the horizontal radius of the breast -- a rare occurrence in a breast not too droopy and suitable for augmentation. If the upper pole is longer than the radius of the breast, then an oval shaped implant could be considered where the upper or long axis of the oval fills higher than the width. This would require a textured surface implant to try to lock it into position. A smooth surface round implant doesn't need texturing to lock it in and a textured surface implant does not guarantee that it will stay in place.
The other factor is forward projection. It is possible to over fill the upper pole of the breast by using an implant with too much forward projection or an implant that is too wide for the width of the breast which forces it to expand into areas where it is not expected.
Breast implants must be fit to the patient and know what effect that is going to have on both the contour and the overall size of the breast. It is not possible to measure this exactly but it can be characterized and before-and-after photos can be helpful to see what effect a given implant has on the breast. On the other hand, I do not find that stuffing bras or trying to match pictures of someone else is helpful.