Great news about the boat..... remember everyone has horror stories to tell you about all types of boat, when i went to pick mine up i'd been reading loads about trailer bearings and frightened myself silly with worry after reading some of the stories i'd heard as i had a 150 mile tow back home, in the end i took out sea start trailer cover just to be safe.
Ok so you can go really silly and spend a lot of money or you can shop around, the internet is a great place to shop for bargains, but remember they are only bargains if A you need them and B you order enough from the same place as to cover the cost of delivery, i bought a pump over the internet rather than pay the price my local chandlers was asking, excited about saving money on my purchase i didn't think about delivery which in the end pushed it up over the price of the local shop !! learned my lesson there, have a look at www.compass24.com
they are offering free delivery at the moment and throw in bags and key floats if you order over a certain amount, plus they are also very cheap, there product is good and the delivery is normally withing a few days.
Search the internet and phone around for insurance quotes, i ended up going with Mardon as they were by far the cheapest and lots of people here recommended them
You need to decide where and when your likely to use your boat and what conditions you want to go out in, then you can start to make up a priority kit list of what you need to have on board with you, it will shock you to see that some boater go to sea with very little safety equiptment at all, see if the previous owner will throw extra bits in with the sale, remember an anchor will cost you £20 a rope £30 plus chain and shackles and your on the thick end of £50 honestly it all adds up, boat jumbles are a really good place to source really cheap gear too, i've not been to one yet but everyone says go.
Something else worth bearing in mind when you do go to get the boat, will they throw in with the sale the spare wheel, trailer jack, wheel brace, trailer wheel lock, trailer board, prop cover and tie down strap, all these things i forgot about and have had to go and buy myself costing me a lot on bits i really shouldn't have had to buy, i picked my boat up and towed it to the nearest shop to buy a prop cover and tie down strap for it, once home i had the engine serviced and boat looked over for problems before i took it out, plus i did my level 2 power boat and a vhf course while still fitting out the boat with bits, vhf license and rya membership are in my opinion a rip off then once you have the rya vhf license you have to apply for your vhf to be registered to use it costing another £20
So bottom line is that i'm trying to say the big things can be accounted for such as boat, engine gps, vhf radio etc but rememebr the little things as they will creep up on you.
Have fun and ask if you need to know anything else.