This question is extremely difficult to answer correctly without seeing you firsthand. I would not be afraid to seek a second opinion from a dentist or orthodontist.
Veneers are a quick option for improving the aesthetics of your teeth but braces may help to achieve optimal results. Braces prior to veneers would allow your dentist to ensure that the roots of your teeth are optimally aligned in a position under the future veneer. For minor space discrepancies this is not likely to be an issue. However, when significant spacing is a factor failing to partially close the space with braces may result in teeth that are excessively widened that do not result in the high quality esthetics the patient desires for their teeth.
The dentistry you require consists of braces and possibly crowns or veneers. If you just had crowns put on the teeth they may appear very wide. Therefore the most likely dental treatment will consist of braces to begin to close the spacing. Crowns and/or veneers may also assist in shaping the teeth to achieve the cosmetic results you want. Cost will depend on the length of time you will have to be in braces. Our practice give complementary consultations to discuss treatment options. Some practices charge up to $150 for an initial consultation. That is probably the norm for dental work in Knoxville TN.
Many times the tooth movement in one arch will be completed a few trays ahead of the opposing arch. It sounds like your upper teeth have moved into place and you still have a little more to go on the bottom teeth. Once the bottom invisalign trays are complete your dentist will probably see you to remove the composite from your teeth. At that appointment your dentist will also discuss retention. You will likely wear a retainer at night so your teeth do not become crooked again. When my patients have an invisalign treatment where one arch finishes before the other I usually advise them to continue to wear their final tray on the arch that finishes first while the remaining trays on the other arch are used.
You have several cosmetic dentistry options.Bonding is the quickest form of dental care to close your gap. This works better the smaller the gap is. A larger gap requires your dentist to make the tooth wider to closer the gap. This may throw off the tooth proportions, resulting in what may look like short fat teeth.Veneers are a form of cosmetic dentistry that may require a small layer of your tooth to be shaved down. A porcelain shell is then fixed to the tooth. Veneers allow the person delivering your dental care to precisely control the width, height and contours of your teeth. This results in a very estheticly controlled look.Braces may be able to close the gap and will keep your teeth natural. My favorite option for esthetic orthodontics is Invisalign. Invisalign uses clear plastic trays to gradually move your teeth to the desired position. In order to determine which restoration is right for you I would suggest finding a dentist who is capable of delivering these three forms of dental care. Talk with him/her to determine your dentistry options and which is best for you!