I'm just 5'9" and i have the regular Tbird with the Tbars which supposedly puts the grips right where the stock bars are. But the stock bars are adjustable so you can bring them back or forward. So i guess you could say the Tbars are where the dealer is SUPPOSED to adjust the stock bars to during setup. In any case, with the Tbars at 5'9" i actually WANT to lean more forward. Unless you get a shield you will find sitting straight up will kill your spine right up in the beginning of your neck on lone rides. When leaned forward the muscles aren't stressed because the weight of your body leaning forward counters the wind. The tbars therefore kill me on long rides sometimes. Used to be ALL the time, but i seem to have adjusted and now it doesn't always happen. At least not on what I call long rides. Do 300+ miles and i think i'd be in trouble.
Of course YMMV, but all i can tell you is what I experienced. But there are aftermarket options i'm sure. As for luggage, there are bags for it. But you can also tie a heck of a lot to a sissybar/rack combo. So i say if you're that lustful of the Tbird go for it. Gut feeling usually can be trusted more than anything else. As for cruising, it will feel like butter all the way to 100. At 100 you won't even be taching 4k. More like 3.7 k. You can cruise at 90-100 all day. To me the bike seems to settle in real smooth and nice at 90 and you're at about 3.2-3k.