I can setup WHMCS with wordpress through WHMCS bridge if your theme is compatible with WHMCS bridge.
There are lot of themes which are compatible with WHMCS bridge. You can find some of those on temeforest.net
[Note:- I am an experienced person working with WHMCS over 5 years and I can do anything in WHMCS. I can setup a complete webhosting business and you will find a fully working system. Contact me for details]