Hi jillyb,
That's a lot to take in probably why no one else has replied
These are just a few observations thrown on the page in no order (its too late to think straight) and
I hope not to offend and don't forget you did ask:
1. The beech nest of tables do not seem to match any of the wood that you already have or are intending to get. I know lots of people will say that you can put any wood together but you seem to want to match and I certainly prefer if they do. They look too light in quality and therefore don't blend with the other wood or maybe its just me
If I was spending money on anything it would be to replace them.
2. There does appear to be too much furniture in the room at the moment so you are right to move the bookcase elsewhere.
3. Plain cream shelves would be too close in colour to the wall so you would be better off with wood possibly to match the units when you decide which ones you are going for.
4. I'm not mad about the pouffe, if you do have one perhaps something with a pattern would be better as it seems to differ a lot from the suite. If you do change the suite one to match that might be better.
5. The present sideboard and T.V. unit are very nice and appear to match the door. You are putting an awful lot of unnecessary expense on yourself if you buy another sideboard etc.
6. I do like the painted cream coffee table that you link to but if you are getting it I think the sideboard to match would suit better
http://www.greatfurnituretradingco.co.uk/somerset-3-door-3-drawer-oak-and-cream-sideboard One thing that I would say about painted stuff is that it is nowhere near as hardwearing as the plain wood. If you got the coffee table and the sideboard you could paint the base of the T.V. unit and leave the top as is and you might get away with that. The handle on it appears to match already but they can be bought quite easily.
7. I certainly wouldn't buy that unit and paint the legs because you might not like it at all then.
I wrecked my head for a few months when I was trying to change our sitting room around. I'm probably old fashioned and perhaps the unmatched options would be better