I'd steer clear of Bottle Domains - I've recently started moving all my domains from them to DIT. The .com.au reseller prices are about $8 more at DIT and .com/.net/.org are $1 more, but it is definitely worth it. Bottle's management interface is useless and usually out of date and their support is the worst I have ever had to deal with.

I have dealt with Louis and Carl at DIT and they have been fantastic. Their management interface, while a little old-school looking, is very simple to use.

I've never used the WHCMS modules though, so I can't comment on those

Which is why you build your own around their API, never had any issues with the API.

I don't remember, do you have to build your own with DIT?

Signed up yesterday with DIT, very happy with their service and everything seems quite fast.

Bottle Domains also has rather old bogon filters. We asked them to update but nothing seems to have changed.

Stu