WAAAY over my head :'(

[katharsis]

Blu-ray player-

Most players should be pretty much up to date right now, but there might be some new features available in the future, which will need a firmware upgrade.
You can either hook the player up to the internet or in most cases you can download the upgrade on the manufacturers website and put it onto a cd, then load it on the player. It's really not hard to do.

TV-

The one you are talking about is probably a rear projection tv. Those are usually quite bulky compared to LCDs or Plasmas. I've had one for about 6 years and it just burnt out last December. It has done an excellent job over the years though. You should go to the stores and have a look at what you like.
If size is not an issue you can go with DLP. Have a look at the differences between 60 and 120 hertz tvs. Or maybe even a projector?
I would try and do some side by side comparison.
If you already know what size tv you would like, it will trim it down to less choices already.

Sound system-

Would you rather want a 5.1 or a 7.1 system?
Looking for speakers- again how much space is available. There are pretty good sized, oversized or small ones...


Now from the description of the place you are giving, will the home theater be in a separate room or in the same area where the pool etc is ?
It would definitely be best to have it set up in a separate room for sound quality alone.

Hope this will help you a little bit...