Congrats on qualifying.
As you say - all opinion. IMHO, it depends on how much you know about shares. Just you 100 Ordinary shares @ £1 - then £12 at Co house. More complicated - different share classes/voting rights - get some advice - accountants can be really good at that sort of thing.
Best structure - again opinion. IMHO - I've been Ltd for 15 years. If I were doing it again I'd probably start sole trader - see how things develop. Might want a business partner in future? - easy to start a partnership - bit more of a pain if Ltd already in place.
What sort of clients are you targeting - some feel more confident if there is a vat reg & Ltd in place and they can check you out at companies house. oooh - clients/competitiors can see how well i'm doing!!
Borrowing dosh -bit easier with Ltd in place.
Customer profile - pulse & cheque book? - Then sole trader
All opinion - all depends and there's probably more involved than outlined above.