Fuji Transonic Frame Size?

Cyclist999
Cyclist999 Posts: 9
edited June 2016 in Road buying advice
Hi guys
I'm looking for my first carbon race bike. I'm a proper cyclist for 6 years and semi-pro for 2-3 years. I am in between different frame sizes of transonic. Could you give some suggestions please?
- My height is 178 cm and have 82 cm inseam lenght
- My old road bike has 540 mm effective TT length and 115 mm stem = 655 mm
(it feels restricted by the way maybe due to tall hoods of tiagra levers)
- I used medium TCR for once which has 555 mm TT and 120mm stem = 675 mm
(it feels rocket like, I locked on target :D, it has pure racy soul)
- And now, most probably I am going to buy Fuji Transonic-2015, which has 545 mm TT and 100mm stem! in medium size (645 mm total reach) and 530 mm TT and 90 mm stem!! in small/medium size (620 mm total reach).
- I will use my new bicycle for race objectives firstly.
-I kinda like high bar-seat drop; I have tried it for once. If I go to medium size, most probably I will lenghten the stem as 20 mm to reach near to TCR feeling ( 545+120 = 665mm)
Or I will go for S/M frame to have little more drop between bar and seat, and to feel more grip on bicycle. So I will lenghten the stem over 90 mm, as 40 mm (130 mm stem length and 530 mm+130 = 660 mm total reach).
Should I go for Medium size or S/M size?
(all values are given in Center to Center)