There is a lot of information here, and it can be a bit much to digest it all at once. So lets start with some basics.
1. There are radar detectors. Lots of choices here, lots of high strung opinion. Wide variation in budget, features, ergonomics, sensitivity, etc. etc.
Bottom line, you get what you pay for and personal preference plays a large role. Your personal driving style can also have a huge impact here. The closer to the edge of the envelope you tend to drive the more you need to spend here, and the more you should learn about behavioral things that can help your odds significantly.
2. Laser detectors. Many radar detectors (rd for short) have laser detection capability. Very few of them have enough sensitivity to pick up the very narrow (compared to radar) beam with any reliability. Even those that do, mostly alert you to the fact that you have just qualified to receive a speeding ticket. The acquisition time is short enough that you are already toast. Still, they are useful to learn where LIDAR traps live and learn to recognize them in advance, but not to actually avoid an unexpected speed trap. The Valentine 1 and a few others in that price range are sensitive enough, but you are still already done for.
3. Radar Jammers. Due to FCC regulations, there is (legally anyway) no such thing.
4. LIDAR Jammers. Since these emit light, they are regulated by the FDA (can't be putting peoples eyes out with those things!). These exist and work very well. They also function as LIDAR detectors, but generally as a side effect of announcing that they are jamming something. Goal number one is to give you enough time to slow down. Once you have slowed, the jammer should be disabled to allow the nice LEO the opportunity to measure your (now legal) speed. A lot of people focus on Jam To Gun (JTG) performance. If you get really focused on this area you can determine the importance of this criteria for yourself. Jammer installation is critical, both in terms of placement and alignment. A poorly installed jammer will work poorly, if at all, even if it is one of the best on the market.
Picking a jammer is one of the more complex tasks, based on your overall goals, budget, car, zodiac sign and political party.
5. Passive LIDAR counter measures. This includes Laser Veil and various license plate protectors. In general these work by making your car (or certain parts of it) less shiny in the infra-red portion of the spectrum that LIDAR uses. This is an application of some of the principles behind stealth technology. Limitations include the size, shape, color of your car and the skill with which you apply the products. Reports indicate that for some cars, this combined with a laser detecting RD can give you a fighting chance. Generally considered to be complementary with jammers.
6. Red light cameras. A fairly new threat, the countermeasures for these are all basically a GPS system tied to a database of red light cameras. It tells you when you are coming up one. Some rds include this capability. Virtually unknown in some areas, but horribly common in others. The trend is that they will be everywhere, perhaps by the middle of next week.
So you need to know your budget, the threats in your area (do they use LIDAR much? Red light cameras? Instant-on?), the rules in your area (are rds illegal, necessitating RDD invisible RDs?) and your vehicle (shiny monster trucks are harder to stealth than dark pointy sports cars).
Lots of information out there, your budget will determine what kinds of counter measures you can afford. A full out RD/Jammer/Veil/GPS based system could easily run you 1500-3000 depending on choices.
In some parts of the country that could be recovered by avoiding 2-3 tickets.