If you have Grade II ptosis, then you more than likely will need a lift. The implants will add volume and very little lift.
330cc Allergan Moderate Profile for Natural Looking Breasts?
Using an implant to avoid a breast lift may be a method of short term prevention but may postpone the inevitable.
To avoid a breast lift with an augmentation would be to not have the augmentation. Performing an augmentation really does not provide a lift, specially if you have grade 2 ptosis. You would need a lift along with the augmentation to have a superior result.
Hope that helps.
Natural result without mastopexy
Without seeing a picture, or having measurements, it's hard to be too definitive regarding the appropriate implant selection. That being said, given that you are a 34C, 330 cc moderate profile sounds in the right ballpark.
The bigger issue is your desire to avoid a mastopexy with grade 2 ptosis. Grade 2 ptosis is not insignificant. Placement of an implant without some type of lift runs the risk of a poor cosmetic result. If you truly wish to avoid the scars associated with a mastopexy, sometimes a circumareolar lift (around the entire circumference of the areola) in combination with an implant can provide a great result.
Your best bet is to discuss this with a board-certified plastic surgeon in your area. Best of luck.
Grade 2 ptosis might be a problem
There is a lot of information that would be required to give you a solid answer. So with the information you have provided I will give you my opinion.
The grade 2 ptosis will not have much improvement with 330 cc implants. If your implants settle into the breast fold and the nipple height is still below your fold it will not look very good. Many women with grade 2 ptosis will need a lift. Make sure to have this discussion with your surgeon.
The size of the implant will probably increase you bra size by one cup, a lot of this depends on your weight and current breast size.
1) Yours is a very common situation, and I have rather long experience. I can tell you that if you have significant sagging, it is a mistake to avoid a breast lift. We have done a lot of revisions in women with sagging who just had implants, and were miserable afterwards.
2) The implant choice you mention sounds reasonable, but it is not your job to select the breast implants. That's part of what you pay your surgeon to do!
Your surgeon should put disposable implant SIZERS in your breasts during surgery, to see exactly what look a particular implant gives you. I think it is a mistake to make the final implant choice in advance. That's why it is important to have an inventory of different implants in the operating room.
Implant choice individualized for most natural results
Two really important considerations for you: First, implant type needs to be based on the base diamter of the breast; if the implant has a diameter larger than the breast, it will be squeezed and the result is ripples. The size of the implant is determined simply by what size you prefer; there are no perfect methods to make the decision but trying implant sizers in a bra that you like is a good place to start. Once you know the size then your surgeon can determine the best implant style to get that size at the right diamter.
Secondly, trying to avoid a lift by going large carries additional risks. The bigger the implant the more likely it is to contribute to further sagging over time. One version of this is the "rock in a sock" as one patient has described it. So just be very careful with that aspect of the decision.
Allergan 330 for natural result
The implant you describe is a moderate size. To answer your question more reliably more information is needed regarding your breast, chest and soft tissue measurements.
Your evaluating surgeon may measure the base width of your natural breast. He/she may also assess the thickness and stretch of the breast tissue. A measurement of the distance from the sternal notch(that v shaped notch at the bottom of your neck in the midline) to the nipple will give an idea of of the degree of nipple descent. The position of the nipple is also assessed relative to the position of your breast on your chest wall.
Your questions can best be answered by a second visit with your board certified plastic surgeon.