Your ‘etc’ covers a pretty large remainder of the process. Assuming you mean a full service, namely briefing-survey-design-planning-b.regs-tender-contract admin-completion, allow for 12 to 15 percent of your projected construction budget for the architect. All other consultants would attract additional fees.
My practice is active in your area and can help with party wall surveys and notifications as well as being able to introduce the other consultants required. Once you’ve had some additional input, ping me a pm.