If you want to stay close to the literal English meaning, you can use "suffoqué".
It has the same literal meaning of loosing one's breath and it also conveys the same emotional meaning as to choke up.
Actually, I just realised that Joubarc's answer is also close to the literal sense of choke up because this is the original meaning of pantois in Ancient French (which is still alive in the English verb to pant from OFr pantoisier, precisely). In French you also have "pantelant".
Another good one is "en avoir le souffle coupé":
ça m'a coupé le souffle!!!
j'en ai eu le soufle coupé
Passing from the lungs to the stomach, you can say:
j'en suis resté estomaqué
A whole bunch of synonyms still, all of which inspired by unpleasant physical consequences provoked by the surprise:
- abasourdi => dumbfound;
- époustouflé => choked up;
- étonné => muted
- médusé => from the Greek Medusa who could turn you to stone if you crossed her gaze;
- pétrifié => petrified, same idea;
- stupéfait stupéfié => awe-inspired;
- ebaubis => made to stammer;