I have built the Tamiya Mid and the Tamiya Late. I also have the Academy waiting for me in a box. I have already test fit the Academy interior into a Tamiya kit and the fit was not acceptable. If you have to get an interior, I hear the TWS is the best one. Their molds have been bought by Tiger Model Designs, so you will have to buy it through them.
IMHO, the Tamiya Late Tiger is the best on the market and it does come with indy tracks. The Tamiya Mid Tiger is just the late version with the earlier road wheels. If I remember correctly, this means there are a few things on the Mid Tiger that need to be corrected.
As far as zim, I would suggest staying away from PE zim and go with a resin manufacturer. IMHO resin just looks better. Don’t ask me what company is best though, because I usually make my zim from putty.
If you want to replace the tracks, there is no question about it, Friulmodel make the best replacement tracks. Yes, the Tamiya Mid and Late Tigers come with indy tracks, but they have two ejector pin marks per track that should be filled. That adds up to a lot of putty!! I have tried both the Friul and the MK tracks and the Friul are by far the best as far as ease of construction and how realistic they look when done.
If you are going to go the PE rout, I am currently using an Aber set, and I have used an Eduard set for one of my tigers. The Aber sets are the most detailed, but the Eduard sets are by far the easiest to construct and will do a lot to preserve your sanity. If you decide to use PE, and it is your first time, get the Eduard set.
Hope this helps, and good luck.