The problem you may find with a "one size fits all" contract is that you're purchasing quite a disparate range of services - the requirements for your hauliers are likely very different to those for a food safety consultant!
Many of these types of business will have their own standard contract / terms of service, so in the first instance I'd ask for copies of those. You can then sign/countersign these if agreeable, or attempt to negotiate specific changes as required.
You may not get quite as much flexibility as writing your own, but IME unless you're a very large company and/or putting a lot of business their way, many suppliers will try very hard to avoid signing anything that isn't their own preferred terms. But at least it means they're doing the work of writing them for you