Passing it on to your kids, great if you can definitely afford it. But think long and hard before setting it all up as a trust. I've been involved in a trust that an older family member set up for my kids' generation. The cost and hassle is considerable. If you're talking about a fund of half a million plus, maybe it makes sense, but for smaller amounts there are a lot of annual overheads (ongoing financial advice and accountancy as well as legal set up costs) that eat into the final amount the kids will get. And don't get me started on how long it takes to administer.
Who else will be trustees? You may think the hassle is worth it, but if you die before your youngest is thirty, other people will have that hassle thrust upon them. My fellow trustees and I have really struggled since the family member died. We have different attitudes to finances and life in general, but are all tied to being responsible for this trust. In a toxic job, you can decide to leave, but it's not so easy with the trust. We have got to the point where relatives we used to be fond of are now people we will avoid at all costs as soon as the trust is wrapped up. You could pay lawyers or accountants to be trustees professionally, I believe, but that then eats even more into the pot.
Also, wouldn't it make sense to help your kids buy a home before they're thirty? If I was you, I'd gift them the money (not sure on the rules of how much you can gift though), invest it, get the kids to sign over responsibility, passwords etc to you, being very vague about how much cash there is, and sort it all out for them until you trust them to use the money to help buy somewhere to live. But outside any formal trust arrangement. Unless you have any particular reasons to think they'll go against your wishes and take the money out and spend it on drugs or fast cars?
Also, if a large amount, is it too late to amend the will so it's an inheritance for them rather than a gift from you? I believe there are advantages to doing that, but I'm not too clear - worth asking the probate lawyer?