DNS switch (A record) to new IP; is site URL only necessary change?

Cheers,

We are moving our old site to a new WordPress installation on a new host. The new site is hosted on an IP through Dreamhost here: http://67.205.25.52/. This WordPress site currently has it’s site URL set to that IP address instead of a domain. The database and WP files are hosted and stored on a Dreamhost directory.

Our old site, kidpower.org, is currently hosted by a separate company with all of our email, etc., with the A record kidpower.org directing to the IP address hosted by that company.

Referencing (http://wordpress.org/support/topic/dns-change-installed-using-ip-address-now-need-to-use-domain-name?replies=4) I wanted to confirm that changing the site URL in the WordPress backend (or the database) is the only change we need to make after creating the new A record.

Once we redirect the new A record for kidpower.org to http://67.205.25.52/, will changing the site URL in WordPress to http://kidpower.org make that change final?

We removed all static linking in the site so all internal links are dynamically updated.

In general, is going about a web transfer in this method a good practice? It is possible clients in the future will need to move hosts, and I want to ensure that there is as little downtime as possible.

Thanks!