Don’t bother. In January I got a CASIO PRO-TREK for an anniversary present. After 4 weeks of use (not even doing any sports), the TITANIUM strap broke, right on the link that holds it to the watch. This is not a normal link and so cannot just be replaced with another link. Also, the way it is connected to the watch means you cannot use ANY other strap except the one for this exact model. My wife took it to the CASIO warranty place in Taipei, who denied it could possibly have broken without some major abuse and told her it would cost 3,000nt to replace. 3000 fucking NT, but it’s not considered important enough to cover in the warranty? Remember this is a watch which has “TOUGH” printed right there on it. It’s supposed to be for climbing up mountains, hence the built-in altimeter, yet this super-strong titanium strap just broke (the link cracked and broke where it is doubled over on itself (IMO a manufacturing defect, which should be replaced regardless of what any warranty says)).
I ended up fabricating my own replacement link. There was no way I was going to fork out 3000nt, especially when the replacement strap might have broken 4 weeks later (with no warranty).
Anyway, I’ve had more luck with Timex (I’ve had several, each of which have lasted several years) and that’s what my next watch will be.
If a normal strap fits on your Ironman, which (unless things have changed) it should, then how about getting an Animal-type one? You can get them at MetrOasis for about 500nt if I remember right.