A Stella finish on a $300 odd dollar price-point reel isn't possible unfortunately, although I think they look pretty sweet.
Not all Shimano reels have strict body to spool sizes, for example, some 1000 size reels could have a 750 or even 500 sized body with a 1000 spool. At least when you compare the 5000 & 6000 models there is definitely a significant spool capacity increase - hope that answers your question.