Angel,
Nice pics - esp the ones showing the fluffly red (pink?) interior!
Steven,
1. Does the RM3800 include installation/workmanship or just the halfcut?
2. I'd say you need a good mechanic who is familiar with Mini's. Any mechanic can do the transfer job but to get it done to satisfaction requires better mechanics.
3. since the old engine is being taken out, take the chance to spruce up the engine bay. eg. remove rust, give it a coat of paint etc. once the new engine goes in, you wont be able to do it.
4. before you put the new engine in, i'd recommend you change all those oil seals which are easily accessible with the engine out. eg. drive shaft into engine seals, seal in the flywheel housing, gear lever seal, gear level sleeve (if loose) etc .. get these done so that you won't get frustrated with oil leak after the engine swap.
5. it'll cost a bit more though to get all these done.
6. what do you intend to do with the old engine?
7. what about the left-over parts from the half-cut? wanna sell? let me know as i'm looking for certain parts.