Acetone, you can buy from eBay. There was a guy on there selling it at 99%+ last time I checked.
I have 25l of it, that I use for cleaning PVC frames and varnishes off things. It works GREAT on PVC for wiping stains off. A few minutes of wiping and the whole thing will look brand new again. I now don't bother masking off PVC and just paint onto it, then wipe the paint off once the walls are dry. Quicker and neater.
Ethyl Acetate shows up SOMETIMES as bottles of acetone free nail polisher remover. That's basically CP grade ethyl acetate.
IPA, you can easily get that from eBay. It's also sold for cleaning white boards or getting marker pens back off school desks. My chemistry teacher had it in a squirty bottle and would go round spritzing the desks mid theory discussion.
Electronics places, like Maplin, sell it for cleaning PCBs as well.
Dichloromethane is a great solvent for really ripping organic material out of things. It's easy to redistill from paint stripper. But acetone will usually work as well and it's far easier to buy it in 99%+ purity bottles than messing around with paint stripper is.
n-hexane is trickier. That used to be in chewing gum remover, I'm not sure if it still is.
I have cyclohexane, but it came from a genuine, account style, laboratory supplier.
Generally, if you need hexane / cyclohexane, there is a good chance Toluene / Xylene will work fine as well. Cyclohexane / xylene / toluene are all the same ring shapes, the latter two just have a methyl or two stuck on. Since there's no functional groups pulling electrons around, they all have essentially zero polarity. You need to be doing something odd for the extra methyls to be any problem. But you can buy those two as paint thinners / brush cleaners in a CP pure state.
Toluene seems to be being phased out. I suspect, because TNT is nitrated toluene. You can't do that with xylene.
Acetone was also a concern because the guys blowing up planes were using liquid bombs where one component was acetone. Of coarse, that looks a lot like water, which is why you're not not allowed bottles full of liquids or gels in your hand luggage. Thank youtube for that as well, and all the tw*ts on there making bombs and pipe bombs, then complaining about terrorists blowing things up or things like columbine, were the two schoolkids had pipe bombs they'd made from a guide.
There is a VERY big difference between making a bit of nitrogen triiodide to make popping noises when people step on it and then packing a piece of steel pipe with high explosive and capping the ends. I'm all for zero censorship, but I do flag every single video I see on there that involves an explosive and piece of metal pipe. There's only one use for something like that, and it's a terrible one. There's a place for that kind of thing, but a site visited by tens of millions of teenagers for video guides is not one of them. For instance, you'd be a pretty bad parent if you're letting your kids watch 18 rated horror / abuse films. My mum was a primary school teacher, and I can assure you, many parents do that and then have their kids on mind altering, amphetamine based drugs like Ritalin when the results come back.
In terms of buying genuine Winchesters of solvents, most of the laboratory suppliers now won't even speak to the public, let alone give them an account. The new initiatives are to essentially restrict any access to any chemical that's not of everyday use or that can be done with an alternative. E.g. a new bill is on the way through to ban things like concentrated sulphuric for drains, along with numerous others. The lab suppliers will usually want to see a business bank account and a VAT number before you get an account.
