Revision - From 335c/365cc to 450cc/500cc?

If you want a larger breast and are disappointed with your size, you do not have to wait for 2-3 years.  You can have your implants exchanged to a larger size at any time.  You skin will stretch just fine.  If the capsule around your implant is soft and no work needs to be done on it, the recovery will be very easy - you may be a little sore from the pressure of a larger implant at first, but it will be much easier than your original operation.  Good luck!

Much of the final “look” achieved after breast augmentation revision surgery  depends on several factors:
1. The initial shape, size (volume of breast tissue), symmetry of the patient's breasts. In general, the better the  preoperative breast appearance the more likely the breast augmentation “look” will be optimal.
2. The experience/skill level of the surgeon is important in determining the final outcome. For example, the accurate and gentle dissection of the breast implant pockets are critical in producing  long-term  well-placed breast implants. I personally think that these 2 factors are more important than any others, including type (saline or silicone)  or model (low/moderate/high profile)  of implant.
3. The type of implant used may  determine the final outcome, especially if the patient does not have significant covering breast or adipose tissue. For example, some surgeons feel that silicone implants have a more natural look and feel than saline implants because silicone gel has a texture that is similar to breast tissue. Each patient differs in the amount of breast tissue that they have.  If a patient has enough breast tissue to cover the implant, the final result will be similar when comparing saline implants versus silicone gel implants.  If a patient has very low body fat and/or very little breast tissue, the silicone gel implants may provide a more "natural" result.
On the other hand, saline implants have some advantages over silicone implants. Silicone implant ruptures are harder to detect. When saline implants rupture, they deflate and the results are seen almost immediately. When silicone implants rupture, the breast often looks and feels the same because the silicone gel may leak into surrounding areas of the breast without a visible difference.  Patients may need an MRI to diagnose a silicone gel rupture.   Saline implants are also less expensive than the silicone gel implants.
Other differences involve how the breast implants are filled. Saline implants are filled after they’re implanted, so saline implants require a smaller incision than prefilled silicone breast implants.
On May 10, 2000, the FDA granted approval of saline-filled breast implants manufactured by Mentor Corporation and McGhan Medical. To date, all other manufacturers’ saline-filled breast implants are considered investigational.
As of 2006, the FDA has approved the use of silicone gel implants manufactured by the Mentor Corporation and Allergan (formerly McGhan) for breast augmentation surgery for patients over the age of 22.
4. The size and model of breast implant used may  make a  significant difference in the final outcome. Therefore, it is very important to communicate your size goals with your surgeon.  In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as “natural” or “C cup” or "fake looking" means different things to different people and therefore prove unhelpful.
Also, as you know, cup size varies depending on who makes the bra; therefore, discussing desired cup  size may also be inaccurate.
I use  intraoperative sizers and place the patient in the upright position to evaluate breast size. Use of these sizers also allow me to select the breast implant profile (low, moderate, moderate plus, high-profile) that would most likely achieve the patient's goals. The patient's goal pictures are hanging on the wall, and allow for direct comparison.
I have found that this system is very helpful in improving the chances of achieving the patient's goals as consistently as possible.
By the way, the most common regret after this operation, is “I wish I was bigger”.
I hope this helps.

It is difficult to say what would be best for you without an exam. You certainly can have them revised at three years.

Without knowing your breast diameter or seeing your breasts currently, I can't say for sure about the specific implant size you would like to go up to, but generally speaking implants can be exchanged for larger ones anytime after the original procedure has completely healed and the swelling totally resolved. I would wait at least 6 months (so waiting 2-3 years is fine). If you go up considerably in size (as you plan), the pocket will have to be enlarged and that means more surgery than just replacing the implants. Probably not as uncomfortable as the original operation, but not painless.