What are the best available technologies for non-invasive plastic surgery on the face? Reducing jowls, turkey neck, sagging eyelids?

Best non-surgical is. Fractional laser resurfacing. I recommend totalfx ultrapulse fractional co2 resurfacing. This modality has the benefit of addressing deep winkles, long-term collagen stimulation/ remodeling as well as improving skin tone, texture, tightening the skin and evening out pigmentation from sun damage. Can treat face, neck, eyelids, chest, hands. Botox & fillers can be used to augment results if needed.
Fillers, Botox but. Filler and Botox but with those problems, likely you won't be satisfied without invasive options.
Multi-modality. There are many treatments available to help rejuvenate the face without facial plastic surgery. These include Botox to relax facial muscles that cause wrinkles, injectable fillers to fill lines and restore volume, and lasers to resurface the skin and treat red and brown spots.
Consider all options. If you are really interested in improving jowls, a turkey neck, and sagging eyelids, don't take the abc (anything but surgery) approach. There are many non-surgical treatments that you will be offered and many will lead to some improvement, but they will not replace what operative procedures can do. Consider all your options: consult a surgeon certified by the am. Board of plastic surgery.
Aging face treatment. Please keep in mind that the most ideal way to deal with signs of aging (jowls, sagging upper eyelids, bulging lower eyelids, fallen cheeks) is still surgical. There are minimally invasive techniques that help to minimize operative time, can be achieved under local anesthetic and have quick recovery times. These are superior to fillers and Botox which are reserved for less striking improvements.
Fillers and botox. Fillers and Botox can be used in a non surgical face lift. However these is no non-invasive way to alter ones appearance. Any time the skin is pierced there is a chance of scarring and complications, be sure your physician has all the tools at his disposal. That is to say if a doctor only has Botox and fillers that is all they can offer.