Concerns of Bottling Blended Beers

I have an idea that I am trying and I needed a little bit of expertise on the bottling side of things.

I am making a Scottish Heavy 70/- in one carboy and a English Cider in a one gallon bottle. My plan is to make a blended beer (not necessarily 1:5 ratio, but whatever ends up tasting good) with the two. I am worried that once I come up with a good blend and bottle it, that it will over ferment in the bottles and possibly explode.

I am sort of on a time crunch since I would like to serve these at a party but I was wondering if you had any tips on how to ensure a proper bottle conditioning? Also - How much priming sugar should I use?

I was thinking about blending and then letting it sit in the carboy for a week or so, and THEN adding the priming sugar before I bottle. but I will end up introducing a lot of oxygen as I am going to have to mix to taste. What do you think?

If both beers are done fermenting, there's no reason to worry. Blend them in the bottling bucket with priming sugar and you're all set. Why are you concerned that it will keep fermenting in the bottle?

If the Cider yeast is more powerful than the Scottish yeast; and once I introduce it to the Cider Yeast to the Scottish ale and it finds extra sugar that the Scottish yeast didn't use, it could possibly start fermenting again? I could possibly be completely wrong on how yeast work. Please inform!

Ah that's a good point, I forgot that the scottish ale yeasts are usually low attenuators. Maybe someone else can chime in with advice!