Let me first state that I'm not a lawyer or anything. This is just my views from what I have seen/read/heard.

This is really hard to say. The point of a caution is to scare people into abiding by the law (ie not do it again). It is a way of dealing with lower crimes that doesn't give you a criminal record but makes it official that you have broken the law (by accepting the caution you are agreeing to this). If you get caught again, they may caution you again (as far as I'm aware there are no limits to the number of cautions you may receive), however they may decide to prosecute (because it is clear you didn't learn your lesson). This really depends on where you live and who is dealing with your case, so there is no real way to tell what will happen. (This is sometimes known as the postcode lottery, and affects NHS as well as policing)

Now, the key bit is how much you grow. The lower the number of plants (don't forget small clones count as whole plants) the more likely they are to let you off (caution you) since you are clearly just growing for yourself. Unfortunately cops tend to overestimate the yield/value of plants and underestimate the shelf life of the final product. They also don't take into account how long it takes to grow the plants (and how much weed you will smoke in that time), so it is very difficult to claim that you are just growing it for yourself unless you keep the number of plants REAL low (like 1-3). If they do prosecute you with that number of plants then you will likely not go to jail, you will most likely get community service and/or a fine. However this will still mean a criminal record (which could interfere with your job/future jobs).

One point you may like to consider, it is illegal for a court to determine your guilt/innocence from prior convictions. So if it did goto court and you had a charge of intent to supply, they would not be allowed to talk about your caution to try and prove this.

The main problem with the war on drugs is the government has brought in extreme legislation that allows them to sieze pretty much whatever they like if it is deemed drug related. That's why they siezed all your grow equipment. It is not illegal to own grow equipment, but they stole it from you since you were using it in an illegal manor. You may want to consider the cost of this equipment (and the near certainty that it will be confiscated if you are ever caught). It can be a lot of money (especially if you get a fine in court) to lose all your equipment over and over.

Really the final answer is upto you. If you are a very cautious person you may want to call it a day. If you are happier to take risks then you may want to try again (if you do this, make sure you learn from your mistakes, ie try to work out how the cops found you out and make sure you fix that, so they cannot use that method next time).

The main problem is you will not find qualified lawyers giving you advice on this forum (it is not a good idea for them to associate themselves with illegal activities and advising people how to break the law). But if you know anyone or can find a lawyer that has experience in this field I suggest you ask them. Do not say "hey is it ok to start growing again?". Just say that you are contacting them on behalf of a friend who has been busted for growing and already has a caution. They will probably want to charge for their time, but their advice will be more reliable/accurate and potentially narrower ranging and higher in detail.