Just a Bath
Keep the bath Ian. Got rid of ours last year for a great big walk in power shower, it's great mind but miss the bath. The river's getting too cold to soak in this time of year!
Hills and Guinness!
What will happen to your rubber duck
Unless you're really attached to your bath and use it lots, let it go. You do get used to not having one. I've not lived permanently in a house with a bath for 16+ years (mind you, some didn't have a shower either!) and hardly ever think about it - admittedly when I do it's when a post-long-run soak would be welcome.
Ian, whatever you do don't get one of those P-shaped 'shower baths' - great for showering in, awful for baths - take absolutely loads of water to get owt like deep enough for a soak, and (at least the one in our house is) the sides are plumb vertical - so you can't get comfy for a lie down anyway, it's more like getting submerged, supported on your elbows, with a neck at right angles. Not conducive to a post-run (or anything at all) relax...
In the 4 years since we got ours (came with the house) I must have had 8 baths - I's swap for a shower cubicle tomorrow, but the kids (4 & 7) like a bath - and it's great for them, loads of room to mess about in (although the specially curved, frameless glass screen spontaneously exploded on them once and sprayed shards of glass everywhere, followed by a night in Calow hospital A&E to stitch the cuts up and pull the fragments out - little lad ended up with dreadlocks after 12 weeks not going near the bathroom)
One day, I hope my greatest contribution to this forum will be related to my experiences running, but for now, have my hatred of p-shaped baths
An ale in the bath is surely the most effective post-run recovery strategy known to mankind? Don't give it up!