I need to complete an A4/3 poster design (InDesign); and design up to 3 new leaflets

Information for the business: Exercise through hiking for women
Industry: Sports and Fitness
Design details: Already have a basic design done in In-Design for A3 size by previous graphic designer who let me down badly on timeframes for finishing and production. I need the existing general poster design finished. It needs some editing as the information is incorrect such as the FB address, the Twitter logo and the service titles. This will mean changing a couple of different pictures. I would also like an A4 version.

I would then like separate single sided leaflets A5 designed along similar lines to promote specific services such as Yoga Hikes and Nordic Hiking. These will promote the service, list the up and coming dates, as well as drive customers to the website to book, or call to book. They will be distributed in sports centres, women's groups to back up the general poster on the noticeboards.

I have the components already in folders for use for the poster which is attached below along with other completed pieces of design.

Not sure if budget is realistic but having wasted £800 getting nothing finished, I'm a bit short of cash flow!
Target audience: Women 35-60
Content on the front/back side and body: Photos and text
Ideas for the visual style: Energetic, warm, friendly
Things to avoid: Too many complicated messages
Preferred colors: As existing: orange, grey are corporate colours
Extra notes: Reliability vital please! Don't want to make another expensive mistake!! Thanks.