Wages and DL repayments aren’t purchases, that’s why they’re not available as a category on purchase invoices. Wages paid through PAYE are usually dealt with via journals, and DL repayments are simply bank transfers into the director’s loan “bank” account.
Vehicle leasing you could add under the “overheads” category, purchase of materials would be “general purchases” (buying things to sell, or to use as part of an identifiable sale rather than just as a general overhead of the whole business), purchases of equipment I’d use the existing asset codes or create new ones if “plant and machinery” and “office equipment” aren’t specific enough, and sub-contractors already exists as a direct expenses code.