Hey Goonbag, none of those things are "cures" for anything. They all have their potential uses in helping you stop using other substances, but that also depends on your own motivations, how you use them, whether you address other issues while using them, etc. Were you told those were the only options by a doctor? Because there's definitely other pharmacotherapies for all those drugs. So if a doctor is telling you that's the only option, without having at least considered (and, for some reason, ruled out) the other options, it might not be a bad idea to get a second opinion.
As Footscrazy noted, taking naltrexone (opioid receptor antagonist) and buprenorphine (mu opioid receptor partial agonist) at the same time would be largely pointless because whichever one has the higher affinity to the receptor (buprenorphine, I suspect), would just prevent the other one from working at those receptors, so you'd just be paying for pills that are doing nothing of much use. But there are other pharmacotherapies for alcohol dependence too. Footscrazy's already pointed out baclofen. I've also heard of acamprosate, which is supposed to help reduce cravings and withdrawal symptoms for alcohol, and can be taken along with opioid replacement pharmacotherapy, though it's apparently only mildly effective. Then there's disulfiram which basically just makes you allergic to alcohol - i.e. it doesn't help with cravings or withdrawals, but if you drink while you're on it, you get violently ill from small amounts of alcohol, creating a strong incentive not to drink (assuming, of course, that you keep taking it every day, which also applies to all the other ones, i.e. it depends on your motivations too, not just the medication).
Naltrexone is supposed to be reasonably effective at reducing alcohol cravings and relapse compared to other treatments, but none of these medications are magic bullets. Naltrexone is also used in treatment of opiate dependence, to block the receptors so people can't get any effect from opioids. The drawback is that some people find naltrexone somewhat aversive (i.e. they feel unpleasant while on it) and I think it's use in treatment of opioid dependence is somewhat less credible than it used to be, particularly due to it rapidly lowering people's tolerance to zero, without solving the person's desire to get high, or the reasons they developed an addiction, so when they get off it, and go use opioids, there's a very high rate of ODs.
Valium is typically the main way they taper people off benzo dependence (and sometimes alcohol dependence), but theoretically any long-acting benzo could be used for that purpose (e.g. clonazepam). But for that to work you really have to be committed to sticking to the tapering regime and not drinking or using extra benzos on top, 'cause once you've developed tolerance, and are trying to reduce it, use of any extra benzos or alcohol will bump it back up very quickly and have you right back where you started. So yeah, you can use long-acting benzos to maintain and taper off, but it's only going to help you get "clean" in the long run with a lot of discipline and patience. Both the suboxone (or methadone, which is another option) and the valium may take a lot longer than a "few months" to get off once you've stabilised on them. If a doctor told you you just need a "few months" on valium and suboxone to "cure" your addiction, then I think they might be telling you what they think you want to hear, not what you really need to know.
