I am getting either a 9/0 penn or daiwa 900h pretty soon, (stilll deciding and comparing the two). I was thinking of going with 1000yds of 80lb or 100lb braid, and then finishing it with 100-200yds of 100lb mono. Does this sound like a good decision? This will be the last shark reel i can buy for awhile and trying to make the most of it. The rod will be a Penn mariner stand up if that helps.
I Say Go With The 9/0 Straight Mono 80lb. You Probably Will Get Striped But The Mono Will Help With Strength 
I cant do 80lb mono lol i freak out about getting spooled. I have locked down on far too many sharks and lost them. Thats why i want braid, so i can let them run and not have to worry.
That Will Work,(I Dont Usually Use Braid) And You Would Get A Lot More Line Distance.
Just trying to learn alot so I can be more successful than I have been before.
do 80-100lb braid topped with 80lb bullbuster mono.
Why only 80lb topshot?
i ment to say 80 to 100lb top shot. sorry about that. 80lb would allow you to have a longer top shot so you could have more yardage. but 100lb is more abrasion resistant.
I'm gonna do 300yds of 100lb power pro under 275yds of 50lb mono with a 100yd 100lb bullbuster topshot.
i would leave the 50lb mono out and do more braid if you can. also hollow core braid would be nicer to since there is no knots in the braid to topshot and it wont get hung up on the guides
Monoxide: Thats Why I Said Do Straight Mono Nothing Gets Caught In The Guides, Learned That The Hard Way When I Had My Old 12/0 Bottom Had 125lb Mono, Top Had 100lb...Blacktip Hit It On Long Key And The Blood Knot Got Caught On The Tip 
Almost Broke My Nose Because Of That 
Monoxide: Thats Why I Said Do Straight Mono Nothing Gets Caught In The Guides, Learned That The Hard Way When I Had My Old 12/0 Bottom Had 125lb Mono, Top Had 100lb...Blacktip Hit It On Long Key And The Blood Knot Got Caught On The Tip
you just have to tie a knot that will pass through. like a albright or a sebile knot. i use a albright for 400lb to 80lb and it passes through my guides.
I was thinking of doing some of that PE china braid (1000yds) but wasnt sure. I have heard its pretty good.