Job description

I just bought 3 bed house semi detached in welling: i want to do some decorations which will include:
1-Taking the wall between sitting and dining room down to make it open lounge
2- painting all the house
3- taking the chimney breat down from dining , sitting, and 2 bedrooms( 2 chimney's, 2 floors) including all the authority approvals, the neighbor has taken the chimney breast years ago)

I need to know the approximate cost for each of these and estimate time to finish (with or without number 3 as i know it takes the most cost and time compared to 1 and 2)
Please let me know if any information required
Thanks