We moved our entire kitchen into the former dining room (after knocking through). For us the focus was getting the most functional space and the extra cost was worth it. I spend a lot of time cooking and the tiny 30s kitchen didn't work for me. Our range cooker went in the chimney breast with the extractor ducted out behind our larder unit. The boiler went to the loft and the washing machine to a new utility. I'd always spend money on getting the layout right and save elsewhere (we reused all our appliances except the range cooker which came off eBay)

We had very similar and unfortunately the back boiler and gas fire came as a unit so we couldnt remove the fire unless replacing the boiler too. We eventually did this once it was on its last legs but until we could afford a new boiler we put a floating shelf above the fire and tried to take the focus away from it (which wasn't very effective to be honest) if we would have to have kept it any longer we were thinking of a bespoke cover for it, a bit like a deeper radiator (removable) cover just to disguise it. Irony is it was a brilliant fire that heated the room up in no time! Not sure how helpful that is but you may decide you'd rather work with it if the expense of replacing a working boiler isn't something you want to do at the moment.

Thanks @rinq and @Maths Wife, there are definitely a lot of things to think about, although it looks like there is a general consensus going on over some of the areas like toilet/boiler etc. I need to check in with the plumber on putting the boiler on the left of the window, as you can see from @rinq plan there is a new wall going on the outside and this may cause issues with required regs distances from windows etc. I like the idea of a wooden counter for the bowls, and carrying this into the alcove would be a neat idea. Im going to change the storage/cupboard from double doors to just one sliding door, with a walk in area and shelves either side. As the two doors are a nightmare. Thanks EVERYONE for the comments and feedback, its really helped.

I think Matt this kind of advice is perhaps beyond the remit of most of the Houzz community. I think you need a Gas Safe engineer to advise you. My old boiler was of a similar age and was fantastic, heated the home beautifully. We only had a new one installed because my husband was retired and qualified for a new one at the time.