You will probably find that your existing drive can play DVDs (and Blu-rays) from any region with the use of Slysoft's AnyDVD (Any DVD HD adds Blu-ray support) - assuming you are running a Windows PC. This sits between the drive and replay software and effectively strips regional encoding on the fly.
They offer (or used to) a short trial period so you can try it before you buy.
Most people with HTPCs I know run AnyDVD HD - it can also solve some tricky HDCP issues.
If your drive is listed here under RPC1 or RPC2 patch then you can modify the drive firmware which allows Windows to change region as many times as you like, no need for paid software: http://ala42.cdfreaks.com/MCSE/