Sounds like its all go!
Would you not be tempted to take the spacers off so you can fit the coilovers, see how it looks and then if you think the wheels still aren't filing the arches enough put them back on and then start rolling? Suppose its as broad as it is long really but you saw how low the TD is, it never scrapes and no arches have had a roller anywhere near them... just a thought but I'm sure it will look awesome either way
Unless you are 100% sure the rear fork bolts aren't seized in you would have to be pretty brave to attempt coilover fitment the day before POL as you may end up having to cut the bolts out which will obviously ruin the bolts and possibly the bush (unless you have all the spares lined up beforehand of course but then you might not need them).
Have you found anywhere more local to do the mapping than Reidy yet?